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Ralston Rsvr Weather Records (USC00056816)

Record envelope, standing records and threshold days for Ralston Rsvr (USC00056816), Colorado, United States, with 49 years of record.

Key Facts for Ralston Rsvr

  • Ralston Rsvr (USC00056816) is a weather station in Colorado, United States at 39.83 latitude and -105.23 longitude, 1,804 m (5,919 ft) above sea level.
  • The station reports from 1978 to 2026, 49 years of record.
  • 1,464 records set at Ralston Rsvr still stand.
  • Records are tracked for prcp, snow, snwd: an element needs 30 years of data to be eligible.
  • Ralston Rsvr set a daily record precipitation of 10.9 mm (0.4 in) on 26 September 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, 39.83 latitude, -105.23 longitude.
  • Elevation: 1,804 m (5,919 ft).
  • Period of record: 1978 to 2026, 49 years.
  • Eligible elements: prcp, snow, snwd.

Daily Record Envelope and 2026

41 days at or beyond a record
Daily record high and record low at Ralston Rsvr, with 2026 drawn through them The band shows the record high and record low for each calendar day at Ralston Rsvr. The lines show the 2026 daily maximum and minimum. 41 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 Ralston Rsvr. The lines show the 2026 daily maximum and minimum. 41 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Ralston Rsvr, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan21.7 C (71.1 F)-25.6 C (-14.1 F)20.0 C (68.0 F)-20.6 C (-5.1 F)
Feb23.3 C (73.9 F)-27.2 C (-17.0 F)21.1 C (70.0 F)-11.7 C (10.9 F)
Mar31.1 C (88.0 F)-21.1 C (-6.0 F)31.1 C (88.0 F)-9.4 C (15.1 F)
Apr28.9 C (84.0 F)-16.7 C (1.9 F)28.3 C (82.9 F)-2.2 C (28.0 F)
May34.4 C (93.9 F)-7.8 C (18.0 F)31.1 C (88.0 F)-1.7 C (28.9 F)
Jun38.9 C (102.0 F)0.0 C (32.0 F)35.0 C (95.0 F)9.4 C (48.9 F)
Jul38.3 C (100.9 F)8.3 C (46.9 F)37.2 C (99.0 F)13.3 C (55.9 F)
Aug37.2 C (99.0 F)5.6 C (42.1 F)37.2 C (99.0 F)10.6 C (51.1 F)
Sep36.7 C (98.1 F)-2.2 C (28.0 F)33.3 C (91.9 F)9.4 C (48.9 F)
Oct30.6 C (87.1 F)-17.2 C (1.0 F)30.6 C (87.1 F)8.3 C (46.9 F)
Nov26.1 C (79.0 F)-22.8 C (-9.0 F)n/an/a
Dec22.2 C (72.0 F)-26.1 C (-15.0 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Ralston Rsvr by the year they were set 1,464 records at Ralston Rsvr still stand. 2020 holds the most, with 62. 0204060801978: 331997: 301998: 401999: 542000: 572001: 352002: 582003: 512004: 522005: 532006: 542007: 252008: 422009: 602010: 312011: 422012: 482013: 532014: 562015: 552016: 402017: 572018: 292019: 472020: 622021: 532022: 582023: 492024: 382025: 532026: 4919782000200420082012201620202024
1,464 records at Ralston Rsvr still stand. 2020 holds the most, with 62.
Standing records at Ralston Rsvr by the year they were set
Year setStanding records
197833
199730
199840
199954
200057
200135
200258
200351
200452
200553
200654
200725
200842
200960
201031
201142
201248
201353
201456
201555
201640
201757
201829
201947
202062
202153
202258
202349
202438
202553
202649

All-Time Record Progression

1 new records
When Ralston Rsvr set new all-time records 1 all-time records were set at Ralston Rsvr between 13 September 2013 and 13 September 2013. Each dot is a new record. Record daily precipitation13 September 2013: Record daily precipitation 266.7 mm (10.5 in)
1 all-time records were set at Ralston Rsvr between 13 September 2013 and 13 September 2013. Each dot is a new record.
When Ralston Rsvr set new all-time records
DateKindDetail
2013-09-13Record daily precipitationRecord daily precipitation 266.7 mm (10.5 in)

Wettest Day of Each Month

Sep: 266.7 mm (10.5 in)
Record daily precipitation for each month at Ralston Rsvr The wettest day on record for each calendar month at Ralston Rsvr. The most was 266.7 mm (10.5 in) on 13 September 2013. 0100200300 Jan: 21.6 mm (0.9 in), 26 January 1998 Jan Feb: 46.7 mm (1.8 in), 3 February 2012 Feb Mar: 64.0 mm (2.5 in), 7 March 1990 Mar Apr: 50.8 mm (2.0 in), 18 April 2009 Apr May: 71.1 mm (2.8 in), 17 May 1995 May Jun: 56.1 mm (2.2 in), 30 June 1987 Jun Jul: 94.5 mm (3.7 in), 17 July 2000 Jul Aug: 54.1 mm (2.1 in), 5 August 1999 Aug Sep: 266.7 mm (10.5 in), 13 September 2013 Sep Oct: 36.8 mm (1.4 in), 10 October 2005 Oct Nov: 26.4 mm (1.0 in), 1 November 1986 Nov Dec: 39.9 mm (1.6 in), 29 December 2022 Dec
The wettest day on record for each calendar month at Ralston Rsvr. The most was 266.7 mm (10.5 in) on 13 September 2013.
Record daily precipitation for each month at Ralston Rsvr
MonthRecord daily precipitation (mm)Date
Jan21.6 mm (0.9 in)26 January 1998
Feb46.7 mm (1.8 in)3 February 2012
Mar64.0 mm (2.5 in)7 March 1990
Apr50.8 mm (2.0 in)18 April 2009
May71.1 mm (2.8 in)17 May 1995
Jun56.1 mm (2.2 in)30 June 1987
Jul94.5 mm (3.7 in)17 July 2000
Aug54.1 mm (2.1 in)5 August 1999
Sep266.7 mm (10.5 in)13 September 2013
Oct36.8 mm (1.4 in)10 October 2005
Nov26.4 mm (1.0 in)1 November 1986
Dec39.9 mm (1.6 in)29 December 2022

Period of Record Coverage

1978 to 2026
Days with data per year at Ralston Rsvr 31 years of record at Ralston Rsvr, 1978 to 2026. 3 years have data for under 90 percent of days and are left out of rankings: 1978, 1997, 2026. 1978: 153 of 365 days1997: 274 of 365 days1998: 333 of 365 days1999: 357 of 365 days2000: 362 of 366 days2001: 360 of 365 days2002: 358 of 365 days2003: 357 of 365 days2004: 364 of 366 days2005: 365 of 365 days2006: 363 of 365 days2007: 334 of 365 days2008: 365 of 366 days2009: 330 of 365 days2010: 362 of 365 days2011: 364 of 365 days2012: 366 of 366 days2013: 361 of 365 days2014: 363 of 365 days2015: 362 of 365 days2016: 345 of 366 days2017: 338 of 365 days2018: 343 of 365 days2019: 359 of 365 days2020: 362 of 366 days2021: 359 of 365 days2022: 362 of 365 days2023: 365 of 365 days2024: 366 of 366 days2025: 364 of 365 days2026: 284 of 365 days200020052010201520202025
31 years of record at Ralston Rsvr, 1978 to 2026. 3 years have data for under 90 percent of days and are left out of rankings: 1978, 1997, 2026.
Days with data per year at Ralston Rsvr
YearDays with dataShare of yearComplete
197815342%No
199727475%No
199833391%Yes
199935798%Yes
200036299%Yes
200136099%Yes
200235898%Yes
200335798%Yes
200436499%Yes
2005365100%Yes
200636399%Yes
200733492%Yes
2008365100%Yes
200933090%Yes
201036299%Yes
2011364100%Yes
2012366100%Yes
201336199%Yes
201436399%Yes
201536299%Yes
201634594%Yes
201733893%Yes
201834394%Yes
201935998%Yes
202036299%Yes
202135998%Yes
202236299%Yes
2023365100%Yes
2024366100%Yes
2025364100%Yes
202628478%No

Latest Records

20
Latest records at Ralston Rsvr
DateStationRecordValueBeat old record byOld record stoodSignificance
26 September 2026Ralston Rsvr, USdaily rain (Provisional)10.9 mm (0.4 in)0.2 mm (0.01 in)29 years12 of 100 (Routine)
25 July 2026Ralston Rsvr, USdaily rain30.2 mm (1.2 in)19.3 mm (0.8 in)27 years36 of 100 (Notable)
25 June 2026Ralston Rsvr, USdaily rain7.9 mm (0.31 in)2.8 mm (0.11 in)4 years8 of 100 (Routine)
9 January 2026Ralston Rsvr, USdaily snowfall12.7 cm (5.0 in)7.6 cm (3.0 in)32 years29 of 100 (Routine)
9 January 2026Ralston Rsvr, USdaily rain7.6 mm (0.30 in)4.8 mm (0.19 in)32 years20 of 100 (Routine)
3 December 2025Ralston Rsvr, USdaily snowfall11.9 cm (4.7 in)4.3 cm (1.7 in)28 years17 of 100 (Routine)
3 December 2025Ralston Rsvr, USdaily rain10.9 mm (0.4 in)2.5 mm (0.10 in)14 years12 of 100 (Routine)
23 September 2025Ralston Rsvr, USdaily rain16.0 mm (0.6 in)8.9 mm (0.35 in)12 years12 of 100 (Routine)
6 June 2025Ralston Rsvr, USdaily rain28.4 mm (1.1 in)14.7 mm (0.6 in)6 years22 of 100 (Routine)
7 May 2025Ralston Rsvr, USdaily rain45.5 mm (1.8 in)27.0 mm (1.1 in)10 years35 of 100 (Notable)
19 April 2025Ralston Rsvr, USdaily snowfall2.5 cm (1.0 in)2.5 cm (1.0 in)46 years20 of 100 (Routine)
30 March 2025Ralston Rsvr, USdaily rain23.6 mm (0.9 in)5.3 mm (0.21 in)32 years18 of 100 (Routine)
29 March 2025Ralston Rsvr, USdaily rain15.7 mm (0.6 in)2.5 mm (0.10 in)31 years15 of 100 (Routine)
21 February 2025Ralston Rsvr, USdaily snowfall15.2 cm (6.0 in)3.8 cm (1.5 in)44 years23 of 100 (Routine)
21 February 2025Ralston Rsvr, USdaily rain13.0 mm (0.5 in)2.3 mm (0.09 in)12 years11 of 100 (Routine)
25 January 2025Ralston Rsvr, USdaily rain14.0 mm (0.6 in)10.2 mm (0.4 in)3 years20 of 100 (Routine)
25 January 2025Ralston Rsvr, USdaily snowfall6.9 cm (2.7 in)4.4 cm (1.7 in)34 years23 of 100 (Routine)
18 January 2025Ralston Rsvr, USdaily snowfall20.3 cm (8.0 in)12.7 cm (5.0 in)2 years32 of 100 (Routine)
18 January 2025Ralston Rsvr, USdaily rain10.2 mm (0.4 in)3.3 mm (0.13 in)2 years12 of 100 (Routine)
26 December 2024Ralston Rsvr, USdaily rain12.4 mm (0.5 in)2.5 mm (0.10 in)10 years11 of 100 (Routine)

Climate Trend

24 complete years, 1999 to 2025
Annual mean temperature at Ralston Rsvr as warming stripes, 1999 to 2025 One stripe for each of 24 complete years at Ralston Rsvr, 1999 to 2025. Blue stripes are years cooler than the station's own mean of 11.0 C (51.7 F); red stripes are warmer. The coolest year was 2008, at 10.0 C (49.9 F), and the warmest was 2024, at 12.2 C (54.0 F). The strongest colour marks a difference of 1.3 C (2.3 F). 1999: 11.0 C, 0.0 C from the station mean2000: 11.1 C, +0.1 C from the station mean2001: 11.1 C, +0.1 C from the station mean2002: 10.5 C, -0.5 C from the station mean2003: 11.1 C, +0.1 C from the station mean2004: 10.7 C, -0.3 C from the station mean2005: 11.1 C, +0.2 C from the station mean2006: 10.8 C, -0.2 C from the station mean2008: 10.0 C, -1.0 C from the station mean2010: 10.3 C, -0.7 C from the station mean2011: 10.2 C, -0.7 C from the station mean2012: 12.1 C, +1.1 C from the station mean2013: 10.0 C, -1.0 C from the station mean2014: 10.3 C, -0.7 C from the station mean2015: 11.1 C, +0.1 C from the station mean2016: 11.2 C, +0.2 C from the station mean2018: 11.0 C, 0.0 C from the station mean2019: 10.2 C, -0.8 C from the station mean2020: 11.6 C, +0.6 C from the station mean2021: 11.8 C, +0.8 C from the station mean2022: 11.3 C, +0.3 C from the station mean2023: 10.8 C, -0.1 C from the station mean2024: 12.2 C, +1.2 C from the station mean2025: 12.0 C, +1.0 C from the station mean199920052010201520202025
One stripe for each of 24 complete years at Ralston Rsvr, 1999 to 2025. Blue stripes are years cooler than the station's own mean of 11.0 C (51.7 F); red stripes are warmer. The coolest year was 2008, at 10.0 C (49.9 F), and the warmest was 2024, at 12.2 C (54.0 F). The strongest colour marks a difference of 1.3 C (2.3 F).
Annual mean temperature at Ralston Rsvr as warming stripes, 1999 to 2025
YearAnnual mean temperatureDifference from the station mean
199911.0 C+0.05 C
200011.1 C+0.09 C
200111.1 C+0.15 C
200210.5 C-0.46 C
200311.1 C+0.11 C
200410.7 C-0.30 C
200511.1 C+0.17 C
200610.8 C-0.15 C
200810.0 C-1.00 C
201010.3 C-0.65 C
201110.2 C-0.72 C
201212.1 C+1.10 C
201310.0 C-0.95 C
201410.3 C-0.66 C
201511.1 C+0.09 C
201611.2 C+0.25 C
201811.0 C-0.01 C
201910.2 C-0.81 C
202011.6 C+0.60 C
202111.8 C+0.80 C
202211.3 C+0.29 C
202310.8 C-0.12 C
202412.2 C+1.24 C
202512.0 C+0.99 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

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 Ralston Rsvr: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)38.9 C (102.0 F)201237.2 C (99.0 F)31
Coldest night (TNn)-27.2 C (-17.0 F)2011-21.7 C (-7.1 F)31
Wettest day (Rx1day)266.7 mm (10.5 in)201341.9 mm (1.6 in)49
Wettest five days (Rx5day)367.5 mm (14.5 in)201364.0 mm (2.5 in)49
Longest dry spell (CDD)51 days202528 days49

Hottest day (TXx)

Hottest day (TXx) at Ralston Rsvr by year The hottest day of the year at Ralston Rsvr, 1978 to 2026. The record is 38.9 C (102.0 F) in 2012, marked on the chart; the median year is 37.2 C (99.0 F). 323436384019801990200020102020Record: 38.9 C (102.0 F) in 2012
The hottest day of the year at Ralston Rsvr, 1978 to 2026. The record is 38.9 C (102.0 F) in 2012, marked on the chart; the median year is 37.2 C (99.0 F).
Hottest day (TXx) at Ralston Rsvr by year
YearHottest day (TXx)
197834.4 C (93.9 F)
1979n/a
1980n/a
1981n/a
1982n/a
1983n/a
1984n/a
1985n/a
1986n/a
1987n/a
1988n/a
1989n/a
1990n/a
1991n/a
1992n/a
1993n/a
1994n/a
1995n/a
1996n/a
199736.7 C (98.1 F)
199837.8 C (100.0 F)
199935.0 C (95.0 F)
200037.8 C (100.0 F)
200136.7 C (98.1 F)
200237.2 C (99.0 F)
200338.3 C (100.9 F)
200437.2 C (99.0 F)
200537.8 C (100.0 F)
200637.2 C (99.0 F)
200736.1 C (97.0 F)
200837.2 C (99.0 F)
200933.9 C (93.0 F)
201036.7 C (98.1 F)
201137.2 C (99.0 F)
201238.9 C (102.0 F)
201336.1 C (97.0 F)
201436.7 C (98.1 F)
201535.0 C (95.0 F)
201636.1 C (97.0 F)
201735.6 C (96.1 F)
201836.7 C (98.1 F)
201937.8 C (100.0 F)
202036.7 C (98.1 F)
202137.2 C (99.0 F)
202237.2 C (99.0 F)
202336.7 C (98.1 F)
202437.8 C (100.0 F)
202537.8 C (100.0 F)
202637.2 C (99.0 F)

Coldest night (TNn)

Coldest night (TNn) at Ralston Rsvr by year The coldest night of the year at Ralston Rsvr, 1978 to 2026. The record is -27.2 C (-17.0 F) in 2011, marked on the chart; the median year is -21.7 C (-7.1 F). -30-25-20-15-10-519801990200020102020Record: -27.2 C (-17.0 F) in 2011
The coldest night of the year at Ralston Rsvr, 1978 to 2026. The record is -27.2 C (-17.0 F) in 2011, marked on the chart; the median year is -21.7 C (-7.1 F).
Coldest night (TNn) at Ralston Rsvr by year
YearColdest night (TNn)
1978-7.8 C (18.0 F)
1979n/a
1980n/a
1981n/a
1982n/a
1983n/a
1984n/a
1985n/a
1986n/a
1987n/a
1988n/a
1989n/a
1990n/a
1991n/a
1992n/a
1993n/a
1994n/a
1995n/a
1996n/a
1997-16.7 C (1.9 F)
1998-23.9 C (-11.0 F)
1999-15.6 C (3.9 F)
2000-16.7 C (1.9 F)
2001-21.7 C (-7.1 F)
2002-18.3 C (-0.9 F)
2003-20.6 C (-5.1 F)
2004-21.1 C (-6.0 F)
2005-21.7 C (-7.1 F)
2006-24.4 C (-11.9 F)
2007-23.9 C (-11.0 F)
2008-25.6 C (-14.1 F)
2009-22.8 C (-9.0 F)
2010-20.6 C (-5.1 F)
2011-27.2 C (-17.0 F)
2012-17.2 C (1.0 F)
2013-22.8 C (-9.0 F)
2014-25.6 C (-14.1 F)
2015-17.8 C (0.0 F)
2016-21.7 C (-7.1 F)
2017-17.2 C (1.0 F)
2018-17.2 C (1.0 F)
2019-24.4 C (-11.9 F)
2020-17.8 C (0.0 F)
2021-25.0 C (-13.0 F)
2022-26.1 C (-15.0 F)
2023-24.4 C (-11.9 F)
2024-25.6 C (-14.1 F)
2025-22.2 C (-8.0 F)
2026-20.6 C (-5.1 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Ralston Rsvr by year The wettest day of the year at Ralston Rsvr, 1978 to 2026. The record is 266.7 mm (10.5 in) in 2013, marked on the chart; the median year is 41.9 mm (1.6 in). 010020030019801990200020102020Record: 266.7 mm (10.5 in) in 2013
The wettest day of the year at Ralston Rsvr, 1978 to 2026. The record is 266.7 mm (10.5 in) in 2013, marked on the chart; the median year is 41.9 mm (1.6 in).
Wettest day (Rx1day) at Ralston Rsvr by year
YearWettest day (Rx1day)
197834.8 mm (1.4 in)
197953.1 mm (2.1 in)
198045.2 mm (1.8 in)
198125.9 mm (1.0 in)
198257.2 mm (2.3 in)
198345.2 mm (1.8 in)
198446.7 mm (1.8 in)
198525.4 mm (1.0 in)
198647.8 mm (1.9 in)
198756.1 mm (2.2 in)
198837.3 mm (1.5 in)
198926.2 mm (1.0 in)
199064.0 mm (2.5 in)
199138.6 mm (1.5 in)
199261.2 mm (2.4 in)
199334.3 mm (1.4 in)
199422.9 mm (0.9 in)
199571.1 mm (2.8 in)
199628.7 mm (1.1 in)
199739.9 mm (1.6 in)
199825.4 mm (1.0 in)
199954.1 mm (2.1 in)
200094.5 mm (3.7 in)
200140.1 mm (1.6 in)
200235.6 mm (1.4 in)
200344.5 mm (1.8 in)
200449.5 mm (1.9 in)
200553.3 mm (2.1 in)
200641.1 mm (1.6 in)
200747.0 mm (1.9 in)
200829.2 mm (1.1 in)
200950.8 mm (2.0 in)
201035.3 mm (1.4 in)
201141.9 mm (1.6 in)
201246.7 mm (1.8 in)
2013266.7 mm (10.5 in)
201445.7 mm (1.8 in)
201545.7 mm (1.8 in)
201638.6 mm (1.5 in)
201737.8 mm (1.5 in)
201837.1 mm (1.5 in)
201925.4 mm (1.0 in)
202035.8 mm (1.4 in)
202141.7 mm (1.6 in)
202239.9 mm (1.6 in)
202359.7 mm (2.4 in)
202442.7 mm (1.7 in)
202545.5 mm (1.8 in)
202630.2 mm (1.2 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Ralston Rsvr by year The wettest five days of the year at Ralston Rsvr, 1978 to 2026. The record is 367.5 mm (14.5 in) in 2013, marked on the chart; the median year is 64.0 mm (2.5 in). 010020030040019801990200020102020Record: 367.5 mm (14.5 in) in 2013
The wettest five days of the year at Ralston Rsvr, 1978 to 2026. The record is 367.5 mm (14.5 in) in 2013, marked on the chart; the median year is 64.0 mm (2.5 in).
Wettest five days (Rx5day) at Ralston Rsvr by year
YearWettest five days (Rx5day)
197868.9 mm (2.7 in)
197971.4 mm (2.8 in)
198049.0 mm (1.9 in)
198133.7 mm (1.3 in)
198279.2 mm (3.1 in)
198385.6 mm (3.4 in)
198453.6 mm (2.1 in)
198541.2 mm (1.6 in)
198673.2 mm (2.9 in)
198786.6 mm (3.4 in)
198869.6 mm (2.7 in)
198961.0 mm (2.4 in)
199081.5 mm (3.2 in)
199161.7 mm (2.4 in)
199289.1 mm (3.5 in)
199348.6 mm (1.9 in)
199445.1 mm (1.8 in)
199583.0 mm (3.3 in)
199681.5 mm (3.2 in)
199773.1 mm (2.9 in)
199854.3 mm (2.1 in)
199978.2 mm (3.1 in)
200096.0 mm (3.8 in)
200150.3 mm (2.0 in)
200248.3 mm (1.9 in)
200397.6 mm (3.8 in)
200453.6 mm (2.1 in)
200553.6 mm (2.1 in)
200654.6 mm (2.1 in)
200768.3 mm (2.7 in)
200862.5 mm (2.5 in)
200982.8 mm (3.3 in)
201079.3 mm (3.1 in)
201164.0 mm (2.5 in)
201257.6 mm (2.3 in)
2013367.5 mm (14.5 in)
201470.3 mm (2.8 in)
201585.1 mm (3.4 in)
201655.8 mm (2.2 in)
201769.3 mm (2.7 in)
201855.2 mm (2.2 in)
201935.3 mm (1.4 in)
202040.1 mm (1.6 in)
202172.3 mm (2.8 in)
202241.2 mm (1.6 in)
2023116.6 mm (4.6 in)
202461.5 mm (2.4 in)
202553.1 mm (2.1 in)
202635.6 mm (1.4 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Ralston Rsvr by year The longest dry spell of the year at Ralston Rsvr, 1978 to 2026. The record is 51 days in 2025, marked on the chart; the median year is 28 days. 10203040506019801990200020102020Record: 51 days in 2025
The longest dry spell of the year at Ralston Rsvr, 1978 to 2026. The record is 51 days in 2025, marked on the chart; the median year is 28 days.
Longest dry spell (CDD) at Ralston Rsvr by year
YearLongest dry spell (CDD)
197828 days
197918 days
198036 days
198125 days
198228 days
198331 days
198450 days
198530 days
198622 days
198725 days
198833 days
198924 days
199019 days
199131 days
199248 days
199325 days
199425 days
199528 days
199625 days
199723 days
199820 days
199933 days
200026 days
200128 days
200243 days
200341 days
200428 days
200530 days
200624 days
200729 days
200847 days
200932 days
201031 days
201128 days
201234 days
201328 days
201428 days
201531 days
201636 days
201738 days
201827 days
201921 days
202043 days
202127 days
202224 days
202326 days
202425 days
202551 days
202636 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

24 years with a frost

Across 24 years with a frost, the median last spring frost at Ralston Rsvr falls on 11 May and the median first autumn frost on 13 October, which leaves a median of 156 days between them.

Frost dates and growing season at Ralston Rsvr
MeasureMedian, all yearsEarliest periodRecent period (1999 to 2025)Recent against earliestFitted trend
Last spring frost11 Mayn/a11 Mayn/an/a
First autumn frost13 Octobern/a13 Octobern/an/a
Growing days156 daysn/a156 daysn/an/a

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

46 years, 1979 to 2025

A day with at least 40.9 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 166.8 mm (6.6 in) of rain is expected about once in 100 years.

Rainfall return levels at Ralston Rsvr: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years40.9 mm (1.6 in)
5 years57.0 mm (2.2 in)
10 years72.6 mm (2.9 in)
25 years100.3 mm (3.9 in)
50 years129.0 mm (5.1 in)Longer than the 46 years of record
100 years166.8 mm (6.6 in)Longer than the 46 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, 46 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: 266.7 mm (10.5 in) in 2013; 94.5 mm (3.7 in) in 2000; 71.1 mm (2.8 in) in 1995.

Download the Data

  • Data for Ralston Rsvr standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Ralston Rsvr 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 2026-10-15 (15 October 2026). Records are computed by this site and are not official.

Data as of . Last revised (2026-10-15).