Built 2026-10-19 (19 October 2026)

Upper San Juan Weather Records (USS0006M03S)

Record envelope, standing records and threshold days for Upper San Juan (USS0006M03S), Colorado, United States, with 49 years of record.

Key Facts for Upper San Juan

  • Upper San Juan (USS0006M03S) is a weather station in Colorado, United States at 37.49 latitude and -106.84 longitude, 3,109 m (10,200 ft) above sea level.
  • The station reports from 1978 to 2026, 49 years of record.
  • 1,464 records set at Upper San Juan still stand.
  • Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
  • Upper San Juan set a daily record high minimum temperature of 1.2 C (34.2 F) on 13 October 2026 (provisional).

Provisional Records

Records set in the last 60 days are provisional until they clear the revision window.

About the Station

  • Location: Colorado, United States, 37.49 latitude, -106.84 longitude.
  • Elevation: 3,109 m (10,200 ft).
  • Period of record: 1978 to 2026, 49 years.
  • Eligible elements: tmax, tmin, prcp.

Daily Record Envelope and 2026

20 days at or beyond a record
Daily record high and record low at Upper San Juan, with 2026 drawn through them The band shows the record high and record low for each calendar day at Upper San Juan. The lines show the 2026 daily maximum and minimum. 20 days in 2026 matched or passed a record. Temperatures are in degrees Celsius. -40-2002040 JanFebMarAprMayJunJulAugSepOctNovDec
The band shows the record high and record low for each calendar day at Upper San Juan. The lines show the 2026 daily maximum and minimum. 20 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Upper San Juan, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan14.7 C (58.5 F)-31.7 C (-25.1 F)8.3 C (46.9 F)-25.5 C (-13.9 F)
Feb15.2 C (59.4 F)-29.6 C (-21.3 F)9.6 C (49.3 F)-25.0 C (-13.0 F)
Mar18.8 C (65.8 F)-30.0 C (-22.0 F)18.2 C (64.8 F)-18.8 C (-1.8 F)
Apr18.8 C (65.8 F)-24.0 C (-11.2 F)14.9 C (58.8 F)-15.1 C (4.8 F)
May26.1 C (79.0 F)-17.3 C (0.9 F)20.3 C (68.5 F)-13.2 C (8.2 F)
Jun27.3 C (81.1 F)-6.7 C (19.9 F)25.2 C (77.4 F)-1.0 C (30.2 F)
Jul28.3 C (82.9 F)-2.9 C (26.8 F)25.9 C (78.6 F)-1.3 C (29.7 F)
Aug26.2 C (79.2 F)-4.1 C (24.6 F)26.2 C (79.2 F)1.9 C (35.4 F)
Sep25.5 C (77.9 F)-11.5 C (11.3 F)22.8 C (73.0 F)-2.5 C (27.5 F)
Oct20.2 C (68.4 F)-22.7 C (-8.9 F)19.5 C (67.1 F)-2.8 C (27.0 F)
Nov16.2 C (61.2 F)-28.8 C (-19.8 F)n/an/a
Dec13.9 C (57.0 F)-33.7 C (-28.7 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Upper San Juan by the year they were set 1,464 records at Upper San Juan still stand. 1996 holds the most, with 52. 02040601983: 311984: 121985: 371986: 391987: 321988: 321989: 391990: 391991: 261992: 381993: 241994: 241995: 421996: 521997: 391998: 371999: 312000: 382001: 232002: 402003: 312004: 292005: 242006: 332007: 322008: 312009: 312010: 352011: 292012: 222013: 492014: 222015: 412016: 302017: 382018: 272019: 462020: 482021: 342022: 372023: 262024: 212025: 412026: 32198319881993199820032008201320182023
1,464 records at Upper San Juan still stand. 1996 holds the most, with 52.
Standing records at Upper San Juan by the year they were set
Year setStanding records
198331
198412
198537
198639
198732
198832
198939
199039
199126
199238
199324
199424
199542
199652
199739
199837
199931
200038
200123
200240
200331
200429
200524
200633
200732
200831
200931
201035
201129
201222
201349
201422
201541
201630
201738
201827
201946
202048
202134
202237
202326
202421
202541
202632

All-Time Record Progression

1 new records
When Upper San Juan set new all-time records 1 all-time records were set at Upper San Juan between 29 July 2017 and 29 July 2017. Each dot is a new record. Record high minimum temperature29 July 2017: Record high minimum temperature 9.9 C (49.8 F)
1 all-time records were set at Upper San Juan between 29 July 2017 and 29 July 2017. Each dot is a new record.
When Upper San Juan set new all-time records
DateKindDetail
2017-07-29Record high minimum temperatureRecord high minimum temperature 9.9 C (49.8 F)

Wettest Day of Each Month

Feb: 106.7 mm (4.2 in)
Record daily precipitation for each month at Upper San Juan The wettest day on record for each calendar month at Upper San Juan. The most was 106.7 mm (4.2 in) on 16 February 1980. 050100150 Jan: 96.5 mm (3.8 in), 11 January 2005 Jan Feb: 106.7 mm (4.2 in), 16 February 1980 Feb Mar: 83.8 mm (3.3 in), 29 March 1979 Mar Apr: 86.4 mm (3.4 in), 18 April 1979 Apr May: 50.8 mm (2.0 in), 8 May 1979 May Jun: 58.4 mm (2.3 in), 30 June 1995 Jun Jul: 58.4 mm (2.3 in), 21 July 1991 Jul Aug: 68.6 mm (2.7 in), 28 August 1993 Aug Sep: 99.1 mm (3.9 in), 19 September 2004 Sep Oct: 99.1 mm (3.9 in), 11 October 2025 Oct Nov: 78.7 mm (3.1 in), 30 November 2007 Nov Dec: 106.7 mm (4.2 in), 7 December 2007 Dec
The wettest day on record for each calendar month at Upper San Juan. The most was 106.7 mm (4.2 in) on 16 February 1980.
Record daily precipitation for each month at Upper San Juan
MonthRecord daily precipitation (mm)Date
Jan96.5 mm (3.8 in)11 January 2005
Feb106.7 mm (4.2 in)16 February 1980
Mar83.8 mm (3.3 in)29 March 1979
Apr86.4 mm (3.4 in)18 April 1979
May50.8 mm (2.0 in)8 May 1979
Jun58.4 mm (2.3 in)30 June 1995
Jul58.4 mm (2.3 in)21 July 1991
Aug68.6 mm (2.7 in)28 August 1993
Sep99.1 mm (3.9 in)19 September 2004
Oct99.1 mm (3.9 in)11 October 2025
Nov78.7 mm (3.1 in)30 November 2007
Dec106.7 mm (4.2 in)7 December 2007

Period of Record Coverage

1983 to 2026
Days with data per year at Upper San Juan 44 years of record at Upper San Juan, 1983 to 2026. 6 years have data for under 90 percent of days and are left out of rankings: 1983, 1984, 1985, 2005, 2013, 2026. 1983: 105 of 365 days1984: 208 of 366 days1985: 286 of 365 days1986: 357 of 365 days1987: 362 of 365 days1988: 364 of 366 days1989: 362 of 365 days1990: 362 of 365 days1991: 364 of 365 days1992: 364 of 366 days1993: 344 of 365 days1994: 353 of 365 days1995: 365 of 365 days1996: 366 of 366 days1997: 364 of 365 days1998: 364 of 365 days1999: 364 of 365 days2000: 366 of 366 days2001: 365 of 365 days2002: 364 of 365 days2003: 332 of 365 days2004: 359 of 366 days2005: 270 of 365 days2006: 365 of 365 days2007: 364 of 365 days2008: 365 of 366 days2009: 364 of 365 days2010: 365 of 365 days2011: 365 of 365 days2012: 365 of 366 days2013: 316 of 365 days2014: 365 of 365 days2015: 365 of 365 days2016: 366 of 366 days2017: 365 of 365 days2018: 358 of 365 days2019: 353 of 365 days2020: 366 of 366 days2021: 365 of 365 days2022: 365 of 365 days2023: 363 of 365 days2024: 334 of 366 days2025: 363 of 365 days2026: 286 of 365 days1990200020102020
44 years of record at Upper San Juan, 1983 to 2026. 6 years have data for under 90 percent of days and are left out of rankings: 1983, 1984, 1985, 2005, 2013, 2026.
Days with data per year at Upper San Juan
YearDays with dataShare of yearComplete
198310529%No
198420857%No
198528678%No
198635798%Yes
198736299%Yes
198836499%Yes
198936299%Yes
199036299%Yes
1991364100%Yes
199236499%Yes
199334494%Yes
199435397%Yes
1995365100%Yes
1996366100%Yes
1997364100%Yes
1998364100%Yes
1999364100%Yes
2000366100%Yes
2001365100%Yes
2002364100%Yes
200333291%Yes
200435998%Yes
200527074%No
2006365100%Yes
2007364100%Yes
2008365100%Yes
2009364100%Yes
2010365100%Yes
2011365100%Yes
2012365100%Yes
201331687%No
2014365100%Yes
2015365100%Yes
2016366100%Yes
2017365100%Yes
201835898%Yes
201935397%Yes
2020366100%Yes
2021365100%Yes
2022365100%Yes
202336399%Yes
202433491%Yes
202536399%Yes
202628678%No

Latest Records

20
Latest records at Upper San Juan
DateStationRecordValueBeat old record byOld record stoodSignificance
13 October 2026Upper San Juan, USdaily high min (Provisional)1.2 C (34.2 F)1.0 C (1.8 F)39 years17 of 100 (Routine)
12 October 2026Upper San Juan, USdaily high min (Provisional)2.4 C (36.3 F)3.4 C (6.1 F)0 years12 of 100 (Routine)
11 October 2026Upper San Juan, USdaily high min (Tie, Provisional)4.8 C (40.6 F)tie0 years1 of 100 (Routine)
3 October 2026Upper San Juan, USdaily high max (Provisional)19.5 C (67.1 F)0.1 C (0.2 F)1 year4 of 100 (Routine)
28 September 2026Upper San Juan, USdaily rain (Provisional)58.4 mm (2.3 in)20.3 mm (0.8 in)20 years26 of 100 (Routine)
28 September 2026Upper San Juan, USdaily high min (Provisional)3.8 C (38.8 F)0.9 C (1.6 F)12 years10 of 100 (Routine)
24 September 2026Upper San Juan, USdaily high min (Provisional)5.6 C (42.1 F)3.5 C (6.3 F)20 years22 of 100 (Routine)
23 September 2026Upper San Juan, USdaily high min (Provisional)5.0 C (41.0 F)0.4 C (0.7 F)19 years10 of 100 (Routine)
17 September 2026Upper San Juan, USdaily rain (Provisional)88.9 mm (3.5 in)27.9 mm (1.1 in)1 year27 of 100 (Routine)
17 September 2026Upper San Juan, USdaily high min (Provisional)7.5 C (45.5 F)2.0 C (3.6 F)12 years14 of 100 (Routine)
14 September 2026Upper San Juan, USdaily high min (Provisional)7.1 C (44.8 F)1.7 C (3.1 F)12 years13 of 100 (Routine)
10 August 2026Upper San Juan, USdaily high max24.8 C (76.6 F)0.3 C (0.5 F)24 years12 of 100 (Routine)
9 August 2026Upper San Juan, USdaily high max25.8 C (78.4 F)0.3 C (0.5 F)25 years12 of 100 (Routine)
7 August 2026Upper San Juan, USdaily high max25.6 C (78.1 F)0.9 C (1.6 F)8 years9 of 100 (Routine)
6 August 2026Upper San Juan, USmonthly high max (Tie)26.2 C (79.2 F)tie23 years5 of 100 (Routine)
5 August 2026Upper San Juan, USdaily high max (Tie)25.3 C (77.5 F)tie16 years2 of 100 (Routine)
4 August 2026Upper San Juan, USdaily high max25.4 C (77.7 F)0.8 C (1.4 F)25 years13 of 100 (Routine)
3 August 2026Upper San Juan, USdaily high max25.4 C (77.7 F)0.9 C (1.6 F)1 year7 of 100 (Routine)
2 August 2026Upper San Juan, USdaily high max25.1 C (77.2 F)0.1 C (0.2 F)25 years11 of 100 (Routine)
28 July 2026Upper San Juan, USdaily high max25.9 C (78.6 F)0.7 C (1.3 F)31 years15 of 100 (Routine)

Climate Trend

36 complete years, 1986 to 2025
Annual mean temperature at Upper San Juan as warming stripes, 1986 to 2025 One stripe for each of 36 complete years at Upper San Juan, 1986 to 2025. Blue stripes are years cooler than the station's own mean of 1.6 C (34.8 F); red stripes are warmer. The coolest year was 1991, at 0.3 C (32.6 F), and the warmest was 2017, at 2.8 C (37.0 F). The strongest colour marks a difference of 1.3 C (2.3 F). 1986: 1.4 C, -0.2 C from the station mean1987: 0.9 C, -0.7 C from the station mean1988: 1.1 C, -0.4 C from the station mean1989: 1.7 C, +0.1 C from the station mean1990: 0.8 C, -0.7 C from the station mean1991: 0.3 C, -1.2 C from the station mean1992: 0.8 C, -0.8 C from the station mean1993: 0.3 C, -1.2 C from the station mean1994: 1.1 C, -0.5 C from the station mean1995: 1.2 C, -0.4 C from the station mean1996: 1.1 C, -0.5 C from the station mean1997: 1.0 C, -0.6 C from the station mean1998: 1.0 C, -0.6 C from the station mean1999: 1.5 C, -0.1 C from the station mean2000: 1.7 C, +0.1 C from the station mean2001: 1.7 C, +0.1 C from the station mean2002: 1.5 C, -0.1 C from the station mean2004: 1.2 C, -0.3 C from the station mean2006: 1.9 C, +0.3 C from the station mean2007: 2.4 C, +0.9 C from the station mean2008: 1.3 C, -0.2 C from the station mean2009: 1.6 C, 0.0 C from the station mean2010: 1.9 C, +0.3 C from the station mean2011: 1.5 C, 0.0 C from the station mean2012: 2.5 C, +0.9 C from the station mean2014: 1.8 C, +0.3 C from the station mean2015: 2.5 C, +0.9 C from the station mean2016: 2.2 C, +0.6 C from the station mean2017: 2.8 C, +1.2 C from the station mean2018: 2.1 C, +0.6 C from the station mean2019: 1.2 C, -0.4 C from the station mean2020: 2.5 C, +0.9 C from the station mean2021: 2.4 C, +0.9 C from the station mean2022: 1.9 C, +0.4 C from the station mean2023: 1.8 C, +0.2 C from the station mean2025: 1.8 C, +0.2 C from the station mean198619901995200020052010201520202025
One stripe for each of 36 complete years at Upper San Juan, 1986 to 2025. Blue stripes are years cooler than the station's own mean of 1.6 C (34.8 F); red stripes are warmer. The coolest year was 1991, at 0.3 C (32.6 F), and the warmest was 2017, at 2.8 C (37.0 F). The strongest colour marks a difference of 1.3 C (2.3 F).
Annual mean temperature at Upper San Juan as warming stripes, 1986 to 2025
YearAnnual mean temperatureDifference from the station mean
19861.4 C-0.21 C
19870.9 C-0.68 C
19881.1 C-0.45 C
19891.7 C+0.13 C
19900.8 C-0.75 C
19910.3 C-1.25 C
19920.8 C-0.78 C
19930.3 C-1.24 C
19941.1 C-0.51 C
19951.2 C-0.40 C
19961.1 C-0.49 C
19971.0 C-0.56 C
19981.0 C-0.56 C
19991.5 C-0.06 C
20001.7 C+0.14 C
20011.7 C+0.10 C
20021.5 C-0.12 C
20041.2 C-0.33 C
20061.9 C+0.34 C
20072.4 C+0.85 C
20081.3 C-0.24 C
20091.6 C+0.03 C
20101.9 C+0.34 C
20111.5 C-0.05 C
20122.5 C+0.91 C
20141.8 C+0.27 C
20152.5 C+0.89 C
20162.2 C+0.62 C
20172.8 C+1.18 C
20182.1 C+0.57 C
20191.2 C-0.36 C
20202.5 C+0.94 C
20212.4 C+0.85 C
20221.9 C+0.37 C
20231.8 C+0.20 C
20251.8 C+0.24 C

The annual mean temperature here has risen by 0.4 C (0.3 to 0.5) per decade over 1986 to 2025. In Fahrenheit: 0.7 F (0.5 to 0.9) per decade. The slope is a straight line fitted to 36 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Upper San Juan
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature0.4 C (0.3 to 0.5) per decade0.7 F (0.5 to 0.9) per decade1986 to 202536Rise
Mean daily maximum0.5 C (0.3 to 0.6) per decade0.8 F (0.5 to 1.1) per decade1986 to 202536Rise
Mean daily minimum0.3 C (0.2 to 0.4) per decade0.5 F (0.3 to 0.8) per decade1986 to 202536Rise

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1978 to 2026
Yearly extremes at Upper San Juan: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)28.3 C (82.9 F)200325.5 C (77.8 F)44
Coldest night (TNn)-33.7 C (-28.7 F)1990-27.2 C (-17.0 F)44
Wettest day (Rx1day)106.7 mm (4.2 in)198068.6 mm (2.7 in)49
Wettest five days (Rx5day)256.5 mm (10.1 in)2005139.7 mm (5.5 in)49
Longest dry spell (CDD)58 days199922 days49

Hottest day (TXx)

Hottest day (TXx) at Upper San Juan by year The hottest day of the year at Upper San Juan, 1978 to 2026. The record is 28.3 C (82.9 F) in 2003, marked on the chart; the median year is 25.5 C (77.8 F). 17.52022.52527.53019801990200020102020Record: 28.3 C (82.9 F) in 2003
The hottest day of the year at Upper San Juan, 1978 to 2026. The record is 28.3 C (82.9 F) in 2003, marked on the chart; the median year is 25.5 C (77.8 F).
Hottest day (TXx) at Upper San Juan by year
YearHottest day (TXx)
1978n/a
1979n/a
1980n/a
1981n/a
1982n/a
198318.8 C (65.8 F)
198422.7 C (72.9 F)
198525.3 C (77.5 F)
198624.9 C (76.8 F)
198724.2 C (75.6 F)
198824.2 C (75.6 F)
198928.0 C (82.4 F)
199027.3 C (81.1 F)
199122.5 C (72.5 F)
199222.5 C (72.5 F)
199323.3 C (73.9 F)
199425.4 C (77.7 F)
199525.2 C (77.4 F)
199624.8 C (76.6 F)
199724.8 C (76.6 F)
199825.8 C (78.4 F)
199925.9 C (78.6 F)
200025.5 C (77.9 F)
200125.2 C (77.4 F)
200227.1 C (80.8 F)
200328.3 C (82.9 F)
200424.5 C (76.1 F)
200527.1 C (80.8 F)
200625.9 C (78.6 F)
200726.5 C (79.7 F)
200824.9 C (76.8 F)
200925.6 C (78.1 F)
201027.7 C (81.9 F)
201125.5 C (77.9 F)
201227.3 C (81.1 F)
201325.6 C (78.1 F)
201425.2 C (77.4 F)
201527.0 C (80.6 F)
201626.2 C (79.2 F)
201725.1 C (77.2 F)
201826.2 C (79.2 F)
201925.0 C (77.0 F)
202027.6 C (81.7 F)
202127.0 C (80.6 F)
202225.2 C (77.4 F)
202327.5 C (81.5 F)
202424.5 C (76.1 F)
202525.0 C (77.0 F)
202626.2 C (79.2 F)

Coldest night (TNn)

Coldest night (TNn) at Upper San Juan by year The coldest night of the year at Upper San Juan, 1978 to 2026. The record is -33.7 C (-28.7 F) in 1990, marked on the chart; the median year is -27.2 C (-17.0 F). -35-32.5-30-27.5-25-22.519801990200020102020Record: -33.7 C (-28.7 F) in 1990
The coldest night of the year at Upper San Juan, 1978 to 2026. The record is -33.7 C (-28.7 F) in 1990, marked on the chart; the median year is -27.2 C (-17.0 F).
Coldest night (TNn) at Upper San Juan by year
YearColdest night (TNn)
1978n/a
1979n/a
1980n/a
1981n/a
1982n/a
1983-26.3 C (-15.3 F)
1984-27.7 C (-17.9 F)
1985-24.7 C (-12.5 F)
1986-26.1 C (-15.0 F)
1987-27.8 C (-18.0 F)
1988-28.6 C (-19.5 F)
1989-31.7 C (-25.1 F)
1990-33.7 C (-28.7 F)
1991-25.0 C (-13.0 F)
1992-23.9 C (-11.0 F)
1993-27.5 C (-17.5 F)
1994-27.9 C (-18.2 F)
1995-26.2 C (-15.2 F)
1996-31.9 C (-25.4 F)
1997-26.8 C (-16.2 F)
1998-27.2 C (-17.0 F)
1999-27.1 C (-16.8 F)
2000-25.9 C (-14.6 F)
2001-25.2 C (-13.4 F)
2002-30.0 C (-22.0 F)
2003-28.8 C (-19.8 F)
2004-28.6 C (-19.5 F)
2005-25.7 C (-14.3 F)
2006-25.9 C (-14.6 F)
2007-29.3 C (-20.7 F)
2008-31.1 C (-24.0 F)
2009-26.5 C (-15.7 F)
2010-25.9 C (-14.6 F)
2011-31.3 C (-24.3 F)
2012-26.1 C (-15.0 F)
2013-31.2 C (-24.2 F)
2014-27.3 C (-17.1 F)
2015-25.0 C (-13.0 F)
2016-28.8 C (-19.8 F)
2017-27.2 C (-17.0 F)
2018-25.0 C (-13.0 F)
2019-26.7 C (-16.1 F)
2020-27.7 C (-17.9 F)
2021-26.7 C (-16.1 F)
2022-28.5 C (-19.3 F)
2023-27.0 C (-16.6 F)
2024-29.6 C (-21.3 F)
2025-28.4 C (-19.1 F)
2026-25.5 C (-13.9 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Upper San Juan by year The wettest day of the year at Upper San Juan, 1978 to 2026. The record is 106.7 mm (4.2 in) in 1980, marked on the chart; the median year is 68.6 mm (2.7 in). 2040608010012019801990200020102020Record: 106.7 mm (4.2 in) in 1980
The wettest day of the year at Upper San Juan, 1978 to 2026. The record is 106.7 mm (4.2 in) in 1980, marked on the chart; the median year is 68.6 mm (2.7 in).
Wettest day (Rx1day) at Upper San Juan by year
YearWettest day (Rx1day)
1978104.1 mm (4.1 in)
197986.4 mm (3.4 in)
1980106.7 mm (4.2 in)
198168.6 mm (2.7 in)
198281.3 mm (3.2 in)
198368.6 mm (2.7 in)
198483.8 mm (3.3 in)
198573.7 mm (2.9 in)
198671.1 mm (2.8 in)
198745.7 mm (1.8 in)
198853.3 mm (2.1 in)
198991.4 mm (3.6 in)
199043.2 mm (1.7 in)
199158.4 mm (2.3 in)
199281.3 mm (3.2 in)
199368.6 mm (2.7 in)
199448.3 mm (1.9 in)
199578.7 mm (3.1 in)
199658.4 mm (2.3 in)
199755.9 mm (2.2 in)
199858.4 mm (2.3 in)
199948.3 mm (1.9 in)
200038.1 mm (1.5 in)
200161.0 mm (2.4 in)
200243.2 mm (1.7 in)
200350.8 mm (2.0 in)
200499.1 mm (3.9 in)
200596.5 mm (3.8 in)
200648.3 mm (1.9 in)
2007106.7 mm (4.2 in)
200888.9 mm (3.5 in)
200973.7 mm (2.9 in)
201078.7 mm (3.1 in)
201171.1 mm (2.8 in)
201248.3 mm (1.9 in)
201348.3 mm (1.9 in)
201440.6 mm (1.6 in)
201561.0 mm (2.4 in)
201671.1 mm (2.8 in)
201755.9 mm (2.2 in)
201858.4 mm (2.3 in)
201976.2 mm (3.0 in)
202078.7 mm (3.1 in)
202171.1 mm (2.8 in)
202258.4 mm (2.3 in)
202355.9 mm (2.2 in)
202461.0 mm (2.4 in)
202599.1 mm (3.9 in)
202688.9 mm (3.5 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Upper San Juan by year The wettest five days of the year at Upper San Juan, 1978 to 2026. The record is 256.5 mm (10.1 in) in 2005, marked on the chart; the median year is 139.7 mm (5.5 in). 5010015020025030019801990200020102020Record: 256.5 mm (10.1 in) in 2005
The wettest five days of the year at Upper San Juan, 1978 to 2026. The record is 256.5 mm (10.1 in) in 2005, marked on the chart; the median year is 139.7 mm (5.5 in).
Wettest five days (Rx5day) at Upper San Juan by year
YearWettest five days (Rx5day)
1978142.3 mm (5.6 in)
1979215.8 mm (8.5 in)
1980170.2 mm (6.7 in)
1981134.6 mm (5.3 in)
1982147.4 mm (5.8 in)
1983152.4 mm (6.0 in)
1984132.1 mm (5.2 in)
1985185.4 mm (7.3 in)
1986152.5 mm (6.0 in)
198778.8 mm (3.1 in)
1988114.4 mm (4.5 in)
1989203.2 mm (8.0 in)
199093.9 mm (3.7 in)
1991137.1 mm (5.4 in)
1992147.3 mm (5.8 in)
1993162.6 mm (6.4 in)
1994121.9 mm (4.8 in)
1995152.4 mm (6.0 in)
1996124.5 mm (4.9 in)
1997147.4 mm (5.8 in)
1998139.7 mm (5.5 in)
1999134.7 mm (5.3 in)
200081.3 mm (3.2 in)
2001119.3 mm (4.7 in)
200286.4 mm (3.4 in)
2003106.6 mm (4.2 in)
2004139.7 mm (5.5 in)
2005256.5 mm (10.1 in)
2006127.0 mm (5.0 in)
2007228.7 mm (9.0 in)
2008190.6 mm (7.5 in)
2009142.3 mm (5.6 in)
2010238.8 mm (9.4 in)
2011160.0 mm (6.3 in)
201288.9 mm (3.5 in)
2013106.8 mm (4.2 in)
201499.1 mm (3.9 in)
2015119.4 mm (4.7 in)
2016106.6 mm (4.2 in)
2017142.3 mm (5.6 in)
2018104.1 mm (4.1 in)
2019165.1 mm (6.5 in)
2020124.4 mm (4.9 in)
2021147.3 mm (5.8 in)
2022124.5 mm (4.9 in)
2023155.0 mm (6.1 in)
2024101.7 mm (4.0 in)
2025254.1 mm (10.0 in)
2026116.8 mm (4.6 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Upper San Juan by year The longest dry spell of the year at Upper San Juan, 1978 to 2026. The record is 58 days in 1999, marked on the chart; the median year is 22 days. 020406019801990200020102020Record: 58 days in 1999
The longest dry spell of the year at Upper San Juan, 1978 to 2026. The record is 58 days in 1999, marked on the chart; the median year is 22 days.
Longest dry spell (CDD) at Upper San Juan by year
YearLongest dry spell (CDD)
197812 days
197928 days
198032 days
198117 days
198222 days
198315 days
198414 days
198519 days
198611 days
198728 days
198820 days
198934 days
199020 days
199118 days
199217 days
199315 days
199424 days
199513 days
199619 days
199723 days
199841 days
199958 days
200022 days
200112 days
200229 days
200315 days
200428 days
200521 days
200625 days
200731 days
200819 days
200915 days
201026 days
201142 days
201245 days
201337 days
201419 days
201521 days
201624 days
201741 days
201817 days
201928 days
202042 days
202119 days
202220 days
202339 days
202424 days
202522 days
202624 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Frost Dates and Growing Season

36 years with a frost

Across 36 years with a frost, the median last spring frost at Upper San Juan falls on 23 June and the median first autumn frost on 10 August, which leaves a median of 48 days between them.

Fitted over all years, the growing season changes by +8.6 days per decade at this station.

Frost dates and growing season at Upper San Juan
MeasureMedian, all yearsEarliest periodRecent period (1992 to 2025)Recent against earliestFitted trend
Last spring frost23 Junen/a23 Junen/a0.0 days per decade
First autumn frost10 Augustn/a16 Augustn/a+8.6 days per decade
Growing days48 daysn/a53 daysn/a+8.6 days per decade

A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.

Rainfall Return Levels

47 years, 1979 to 2025

A day with at least 65.3 mm (2.6 in) of rain is expected about once in 2 years. A day with at least 119.9 mm (4.7 in) of rain is expected about once in 100 years.

Rainfall return levels at Upper San Juan: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years65.3 mm (2.6 in)
5 years82.1 mm (3.2 in)
10 years92.3 mm (3.6 in)
25 years104.2 mm (4.1 in)
50 years112.3 mm (4.4 in)Longer than the 47 years of record
100 years119.9 mm (4.7 in)Longer than the 47 years of record

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 47 years of values from 1979 to 2025.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 106.7 mm (4.2 in) in 1980; 106.7 mm (4.2 in) in 2007; 99.1 mm (3.9 in) in 2004.

Download the Data

  • Data for Upper San Juan standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Upper San Juan threshold days by year: CSV or JSON. Field meanings are on the data page.

Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-17 (17 October 2026). Records are computed by this site and are not official.

Data as of . Last revised (2026-10-17).