Built 2026-10-19 (19 October 2026)

Merchant Valley Weather Records (USS0012L12S)

Record envelope, standing records and threshold days for Merchant Valley (USS0012L12S), Utah, United States, with 47 years of record.

Key Facts for Merchant Valley

  • Merchant Valley (USS0012L12S) is a weather station in Utah, United States at 38.30 latitude and -112.44 longitude, 2,653 m (8,703 ft) above sea level.
  • The station reports from 1980 to 2026, 47 years of record.
  • 1,464 records set at Merchant Valley still stand.
  • Records are tracked for prcp: an element needs 30 years of data to be eligible.
  • Merchant Valley set a daily record precipitation of 15.2 mm (0.6 in) on 13 April 2026.

About the Station

  • Location: Utah, United States, 38.30 latitude, -112.44 longitude.
  • Elevation: 2,653 m (8,703 ft).
  • Period of record: 1980 to 2026, 47 years.
  • Eligible elements: prcp.

Daily Record Envelope and 2026

32 days at or beyond a record
Daily record high and record low at Merchant Valley, with 2026 drawn through them The band shows the record high and record low for each calendar day at Merchant Valley. The lines show the 2026 daily maximum and minimum. 32 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 Merchant Valley. The lines show the 2026 daily maximum and minimum. 32 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Merchant Valley, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan14.6 C (58.3 F)-29.2 C (-20.6 F)11.7 C (53.1 F)-16.4 C (2.5 F)
Feb14.6 C (58.3 F)-25.5 C (-13.9 F)12.9 C (55.2 F)-19.6 C (-3.3 F)
Mar22.3 C (72.1 F)-21.7 C (-7.1 F)22.3 C (72.1 F)-12.2 C (10.0 F)
Apr20.7 C (69.3 F)-19.8 C (-3.6 F)16.4 C (61.5 F)-11.0 C (12.2 F)
May25.4 C (77.7 F)-9.2 C (15.4 F)23.6 C (74.5 F)-5.3 C (22.5 F)
Jun29.1 C (84.4 F)-9.4 C (15.1 F)27.1 C (80.8 F)1.8 C (35.2 F)
Jul30.8 C (87.4 F)1.2 C (34.2 F)n/an/a
Aug30.1 C (86.2 F)-0.6 C (30.9 F)n/an/a
Sep28.4 C (83.1 F)-7.9 C (17.8 F)n/an/a
Oct23.6 C (74.5 F)-19.9 C (-3.8 F)n/an/a
Nov17.2 C (63.0 F)-24.8 C (-12.6 F)n/an/a
Dec13.5 C (56.3 F)-26.8 C (-16.2 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Merchant Valley by the year they were set 1,464 records at Merchant Valley still stand. 2022 holds the most, with 87. 02550751002003: 332004: 532005: 582006: 592007: 582008: 652009: 582010: 692011: 662012: 592013: 822014: 492015: 652016: 542017: 672018: 412019: 602020: 712021: 602022: 872023: 492024: 682025: 732026: 6020032006200920122015201820212024
1,464 records at Merchant Valley still stand. 2022 holds the most, with 87.
Standing records at Merchant Valley by the year they were set
Year setStanding records
200333
200453
200558
200659
200758
200865
200958
201069
201166
201259
201382
201449
201565
201654
201767
201841
201960
202071
202160
202287
202349
202468
202573
202660

Wettest Day of Each Month

Aug: 116.8 mm (4.6 in)
Record daily precipitation for each month at Merchant Valley The wettest day on record for each calendar month at Merchant Valley. The most was 116.8 mm (4.6 in) on 2 August 1988. 050100150 Jan: 58.4 mm (2.3 in), 23 January 1997 Jan Feb: 53.3 mm (2.1 in), 8 February 1994 Feb Mar: 48.3 mm (1.9 in), 2 March 1989 Mar Apr: 40.6 mm (1.6 in), 26 April 2014 Apr May: 53.3 mm (2.1 in), 3 May 1999 May Jun: 86.4 mm (3.4 in), 23 June 2001 Jun Jul: 55.9 mm (2.2 in), 26 July 2019 Jul Aug: 116.8 mm (4.6 in), 2 August 1988 Aug Sep: 50.8 mm (2.0 in), 9 September 1997 Sep Oct: 43.2 mm (1.7 in), 4 October 2008 Oct Nov: 63.5 mm (2.5 in), 26 November 2024 Nov Dec: 61.0 mm (2.4 in), 20 December 2010 Dec
The wettest day on record for each calendar month at Merchant Valley. The most was 116.8 mm (4.6 in) on 2 August 1988.
Record daily precipitation for each month at Merchant Valley
MonthRecord daily precipitation (mm)Date
Jan58.4 mm (2.3 in)23 January 1997
Feb53.3 mm (2.1 in)8 February 1994
Mar48.3 mm (1.9 in)2 March 1989
Apr40.6 mm (1.6 in)26 April 2014
May53.3 mm (2.1 in)3 May 1999
Jun86.4 mm (3.4 in)23 June 2001
Jul55.9 mm (2.2 in)26 July 2019
Aug116.8 mm (4.6 in)2 August 1988
Sep50.8 mm (2.0 in)9 September 1997
Oct43.2 mm (1.7 in)4 October 2008
Nov63.5 mm (2.5 in)26 November 2024
Dec61.0 mm (2.4 in)20 December 2010

Period of Record Coverage

2003 to 2026
Days with data per year at Merchant Valley 24 years of record at Merchant Valley, 2003 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 2003, 2026. 2003: 195 of 365 days2004: 366 of 366 days2005: 365 of 365 days2006: 365 of 365 days2007: 365 of 365 days2008: 365 of 366 days2009: 365 of 365 days2010: 365 of 365 days2011: 365 of 365 days2012: 366 of 366 days2013: 365 of 365 days2014: 365 of 365 days2015: 365 of 365 days2016: 366 of 366 days2017: 365 of 365 days2018: 365 of 365 days2019: 365 of 365 days2020: 366 of 366 days2021: 365 of 365 days2022: 348 of 365 days2023: 365 of 365 days2024: 366 of 366 days2025: 365 of 365 days2026: 173 of 365 days20052010201520202025
24 years of record at Merchant Valley, 2003 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 2003, 2026.
Days with data per year at Merchant Valley
YearDays with dataShare of yearComplete
200319553%No
2004366100%Yes
2005365100%Yes
2006365100%Yes
2007365100%Yes
2008365100%Yes
2009365100%Yes
2010365100%Yes
2011365100%Yes
2012366100%Yes
2013365100%Yes
2014365100%Yes
2015365100%Yes
2016366100%Yes
2017365100%Yes
2018365100%Yes
2019365100%Yes
2020366100%Yes
2021365100%Yes
202234895%Yes
2023365100%Yes
2024366100%Yes
2025365100%Yes
202617347%No

Latest Records

20
Latest records at Merchant Valley
DateStationRecordValueBeat old record byOld record stoodSignificance
13 April 2026Merchant Valley, USdaily rain15.2 mm (0.6 in)7.6 mm (0.30 in)29 years20 of 100 (Routine)
1 January 2026Merchant Valley, USdaily rain (Tie)17.8 mm (0.7 in)tie3 years1 of 100 (Routine)
16 November 2025Merchant Valley, USdaily rain15.2 mm (0.6 in)2.5 mm (0.10 in)31 years16 of 100 (Routine)
4 September 2025Merchant Valley, USdaily rain17.8 mm (0.7 in)2.6 mm (0.10 in)2 years7 of 100 (Routine)
27 August 2025Merchant Valley, USdaily rain12.7 mm (0.5 in)7.6 mm (0.30 in)36 years20 of 100 (Routine)
23 August 2025Merchant Valley, USdaily rain20.3 mm (0.8 in)5.1 mm (0.20 in)22 years15 of 100 (Routine)
21 July 2025Merchant Valley, USdaily rain (Tie)5.1 mm (0.20 in)tie16 years2 of 100 (Routine)
28 April 2025Merchant Valley, USdaily rain12.7 mm (0.5 in)2.5 mm (0.10 in)20 years13 of 100 (Routine)
13 March 2025Merchant Valley, USdaily rain (Tie)17.8 mm (0.7 in)tie15 years2 of 100 (Routine)
14 February 2025Merchant Valley, USdaily rain25.4 mm (1.0 in)10.2 mm (0.4 in)30 years27 of 100 (Routine)
26 November 2024Merchant Valley, USmonthly rain63.5 mm (2.5 in)17.8 mm (0.7 in)41 years49 of 100 (Notable)
12 August 2024Merchant Valley, USdaily rain27.9 mm (1.1 in)5.0 mm (0.20 in)30 years18 of 100 (Routine)
20 July 2024Merchant Valley, USdaily rain (Tie)17.8 mm (0.7 in)tie26 years2 of 100 (Routine)
2 February 2024Merchant Valley, USdaily rain25.4 mm (1.0 in)17.8 mm (0.7 in)37 years40 of 100 (Notable)
13 January 2024Merchant Valley, USdaily rain22.9 mm (0.9 in)5.1 mm (0.20 in)25 years18 of 100 (Routine)
19 November 2023Merchant Valley, USdaily rain25.4 mm (1.0 in)2.5 mm (0.10 in)4 years8 of 100 (Routine)
2 October 2023Merchant Valley, USdaily rain (Tie)17.8 mm (0.7 in)tie20 years2 of 100 (Routine)
4 September 2023Merchant Valley, USdaily rain15.2 mm (0.6 in)7.6 mm (0.30 in)32 years20 of 100 (Routine)
2 September 2023Merchant Valley, USdaily rain (Tie)2.5 mm (0.10 in)tie28 years3 of 100 (Routine)
31 August 2023Merchant Valley, USdaily rain (Tie)10.2 mm (0.4 in)tie9 years1 of 100 (Routine)

Climate Trend

21 complete years, 2004 to 2025
Annual mean temperature at Merchant Valley as warming stripes, 2004 to 2025 One stripe for each of 21 complete years at Merchant Valley, 2004 to 2025. Blue stripes are years cooler than the station's own mean of 5.0 C (41.0 F); red stripes are warmer. The coolest year was 2019, at 4.0 C (39.2 F), and the warmest was 2025, at 6.2 C (43.1 F). The strongest colour marks a difference of 1.2 C (2.2 F). 2004: 4.5 C, -0.5 C from the station mean2005: 4.9 C, -0.1 C from the station mean2006: 4.7 C, -0.3 C from the station mean2007: 5.1 C, +0.1 C from the station mean2009: 4.4 C, -0.6 C from the station mean2010: 4.3 C, -0.7 C from the station mean2011: 4.1 C, -0.9 C from the station mean2012: 5.4 C, +0.4 C from the station mean2013: 4.2 C, -0.8 C from the station mean2014: 5.3 C, +0.3 C from the station mean2015: 5.5 C, +0.5 C from the station mean2016: 5.4 C, +0.4 C from the station mean2017: 5.8 C, +0.8 C from the station mean2018: 5.3 C, +0.3 C from the station mean2019: 4.0 C, -1.0 C from the station mean2020: 5.6 C, +0.6 C from the station mean2021: 5.5 C, +0.5 C from the station mean2022: 4.9 C, -0.1 C from the station mean2023: 4.3 C, -0.7 C from the station mean2024: 5.7 C, +0.7 C from the station mean2025: 6.2 C, +1.2 C from the station mean20042006200820102012201420162018202020222024
One stripe for each of 21 complete years at Merchant Valley, 2004 to 2025. Blue stripes are years cooler than the station's own mean of 5.0 C (41.0 F); red stripes are warmer. The coolest year was 2019, at 4.0 C (39.2 F), and the warmest was 2025, at 6.2 C (43.1 F). The strongest colour marks a difference of 1.2 C (2.2 F).
Annual mean temperature at Merchant Valley as warming stripes, 2004 to 2025
YearAnnual mean temperatureDifference from the station mean
20044.5 C-0.52 C
20054.9 C-0.14 C
20064.7 C-0.32 C
20075.1 C+0.14 C
20094.4 C-0.64 C
20104.3 C-0.72 C
20114.1 C-0.93 C
20125.4 C+0.40 C
20134.2 C-0.76 C
20145.3 C+0.31 C
20155.5 C+0.49 C
20165.4 C+0.37 C
20175.8 C+0.84 C
20185.3 C+0.26 C
20194.0 C-0.99 C
20205.6 C+0.57 C
20215.5 C+0.45 C
20224.9 C-0.10 C
20234.3 C-0.66 C
20245.7 C+0.74 C
20256.2 C+1.18 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

1980 to 2026
Yearly extremes at Merchant Valley: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)30.8 C (87.4 F)200328.7 C (83.7 F)24
Coldest night (TNn)-29.2 C (-20.6 F)2013-23.0 C (-9.4 F)24
Wettest day (Rx1day)116.8 mm (4.6 in)198840.6 mm (1.6 in)47
Wettest five days (Rx5day)172.8 mm (6.8 in)201071.2 mm (2.8 in)47
Longest dry spell (CDD)69 days201231 days47

Hottest day (TXx)

Hottest day (TXx) at Merchant Valley by year The hottest day of the year at Merchant Valley, 1980 to 2026. The record is 30.8 C (87.4 F) in 2003, marked on the chart; the median year is 28.7 C (83.7 F). 26272829303119801990200020102020Record: 30.8 C (87.4 F) in 2003
The hottest day of the year at Merchant Valley, 1980 to 2026. The record is 30.8 C (87.4 F) in 2003, marked on the chart; the median year is 28.7 C (83.7 F).
Hottest day (TXx) at Merchant Valley by year
YearHottest day (TXx)
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
1997n/a
1998n/a
1999n/a
2000n/a
2001n/a
2002n/a
200330.8 C (87.4 F)
200427.2 C (81.0 F)
200529.8 C (85.6 F)
200629.6 C (85.3 F)
200729.8 C (85.6 F)
200828.9 C (84.0 F)
200928.3 C (82.9 F)
201027.5 C (81.5 F)
201126.8 C (80.2 F)
201227.5 C (81.5 F)
201328.8 C (83.8 F)
201427.0 C (80.6 F)
201527.7 C (81.9 F)
201629.3 C (84.7 F)
201728.6 C (83.5 F)
201828.2 C (82.8 F)
201927.0 C (80.6 F)
202030.1 C (86.2 F)
202130.7 C (87.3 F)
202228.4 C (83.1 F)
202330.0 C (86.0 F)
202430.6 C (87.1 F)
202529.6 C (85.3 F)
202627.1 C (80.8 F)

Coldest night (TNn)

Coldest night (TNn) at Merchant Valley by year The coldest night of the year at Merchant Valley, 1980 to 2026. The record is -29.2 C (-20.6 F) in 2013, marked on the chart; the median year is -23.0 C (-9.4 F). -30-27.5-25-22.5-20-17.519801990200020102020Record: -29.2 C (-20.6 F) in 2013
The coldest night of the year at Merchant Valley, 1980 to 2026. The record is -29.2 C (-20.6 F) in 2013, marked on the chart; the median year is -23.0 C (-9.4 F).
Coldest night (TNn) at Merchant Valley by year
YearColdest night (TNn)
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
1997n/a
1998n/a
1999n/a
2000n/a
2001n/a
2002n/a
2003-21.1 C (-6.0 F)
2004-25.7 C (-14.3 F)
2005-21.3 C (-6.3 F)
2006-25.0 C (-13.0 F)
2007-27.4 C (-17.3 F)
2008-26.5 C (-15.7 F)
2009-23.3 C (-9.9 F)
2010-26.8 C (-16.2 F)
2011-27.1 C (-16.8 F)
2012-20.5 C (-4.9 F)
2013-29.2 C (-20.6 F)
2014-23.0 C (-9.4 F)
2015-20.9 C (-5.6 F)
2016-24.0 C (-11.2 F)
2017-22.5 C (-8.5 F)
2018-23.6 C (-10.5 F)
2019-25.2 C (-13.4 F)
2020-23.0 C (-9.4 F)
2021-20.7 C (-5.3 F)
2022-22.3 C (-8.1 F)
2023-22.2 C (-8.0 F)
2024-19.8 C (-3.6 F)
2025-20.1 C (-4.2 F)
2026-19.6 C (-3.3 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Merchant Valley by year The wettest day of the year at Merchant Valley, 1980 to 2026. The record is 116.8 mm (4.6 in) in 1988, marked on the chart; the median year is 40.6 mm (1.6 in). 025507510012519801990200020102020Record: 116.8 mm (4.6 in) in 1988
The wettest day of the year at Merchant Valley, 1980 to 2026. The record is 116.8 mm (4.6 in) in 1988, marked on the chart; the median year is 40.6 mm (1.6 in).
Wettest day (Rx1day) at Merchant Valley by year
YearWettest day (Rx1day)
198017.8 mm (0.7 in)
198130.5 mm (1.2 in)
198245.7 mm (1.8 in)
198350.8 mm (2.0 in)
198438.1 mm (1.5 in)
198543.2 mm (1.7 in)
198633.0 mm (1.3 in)
198735.6 mm (1.4 in)
1988116.8 mm (4.6 in)
198948.3 mm (1.9 in)
199038.1 mm (1.5 in)
199135.6 mm (1.4 in)
199240.6 mm (1.6 in)
199345.7 mm (1.8 in)
199453.3 mm (2.1 in)
199527.9 mm (1.1 in)
199627.9 mm (1.1 in)
199758.4 mm (2.3 in)
199825.4 mm (1.0 in)
199953.3 mm (2.1 in)
200040.6 mm (1.6 in)
200186.4 mm (3.4 in)
200220.3 mm (0.8 in)
200327.9 mm (1.1 in)
200438.1 mm (1.5 in)
200533.0 mm (1.3 in)
200633.0 mm (1.3 in)
200750.8 mm (2.0 in)
200843.2 mm (1.7 in)
200945.7 mm (1.8 in)
201061.0 mm (2.4 in)
201135.6 mm (1.4 in)
201235.6 mm (1.4 in)
201340.6 mm (1.6 in)
201450.8 mm (2.0 in)
201535.6 mm (1.4 in)
201648.3 mm (1.9 in)
201761.0 mm (2.4 in)
201833.0 mm (1.3 in)
201955.9 mm (2.2 in)
202017.8 mm (0.7 in)
202148.3 mm (1.9 in)
202245.7 mm (1.8 in)
202338.1 mm (1.5 in)
202463.5 mm (2.5 in)
202525.4 mm (1.0 in)
202622.9 mm (0.9 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Merchant Valley by year The wettest five days of the year at Merchant Valley, 1980 to 2026. The record is 172.8 mm (6.8 in) in 2010, marked on the chart; the median year is 71.2 mm (2.8 in). 05010015020019801990200020102020Record: 172.8 mm (6.8 in) in 2010
The wettest five days of the year at Merchant Valley, 1980 to 2026. The record is 172.8 mm (6.8 in) in 2010, marked on the chart; the median year is 71.2 mm (2.8 in).
Wettest five days (Rx5day) at Merchant Valley by year
YearWettest five days (Rx5day)
198033.0 mm (1.3 in)
198158.5 mm (2.3 in)
198283.8 mm (3.3 in)
1983116.9 mm (4.6 in)
198476.2 mm (3.0 in)
198599.0 mm (3.9 in)
198673.7 mm (2.9 in)
198753.4 mm (2.1 in)
1988134.6 mm (5.3 in)
198953.3 mm (2.1 in)
199071.2 mm (2.8 in)
199171.2 mm (2.8 in)
199276.2 mm (3.0 in)
199376.1 mm (3.0 in)
199463.4 mm (2.5 in)
199573.6 mm (2.9 in)
199663.5 mm (2.5 in)
199788.9 mm (3.5 in)
199855.9 mm (2.2 in)
199978.7 mm (3.1 in)
200053.3 mm (2.1 in)
200199.1 mm (3.9 in)
200253.4 mm (2.1 in)
200355.8 mm (2.2 in)
200486.4 mm (3.4 in)
200568.7 mm (2.7 in)
200653.4 mm (2.1 in)
200783.8 mm (3.3 in)
200855.9 mm (2.2 in)
200973.7 mm (2.9 in)
2010172.8 mm (6.8 in)
201171.1 mm (2.8 in)
201255.9 mm (2.2 in)
201358.4 mm (2.3 in)
201458.4 mm (2.3 in)
201560.9 mm (2.4 in)
201661.0 mm (2.4 in)
201793.9 mm (3.7 in)
201886.3 mm (3.4 in)
201978.7 mm (3.1 in)
202033.1 mm (1.3 in)
202183.8 mm (3.3 in)
202278.7 mm (3.1 in)
202383.9 mm (3.3 in)
202476.2 mm (3.0 in)
202548.3 mm (1.9 in)
202640.7 mm (1.6 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Merchant Valley by year The longest dry spell of the year at Merchant Valley, 1980 to 2026. The record is 69 days in 2012, marked on the chart; the median year is 31 days. 02040608019801990200020102020Record: 69 days in 2012
The longest dry spell of the year at Merchant Valley, 1980 to 2026. The record is 69 days in 2012, marked on the chart; the median year is 31 days.
Longest dry spell (CDD) at Merchant Valley by year
YearLongest dry spell (CDD)
198012 days
198133 days
198230 days
198322 days
198422 days
198526 days
198637 days
198721 days
198823 days
198931 days
199023 days
199133 days
199227 days
199345 days
199468 days
199535 days
199641 days
199737 days
199818 days
199930 days
200031 days
200118 days
200241 days
200350 days
200429 days
200526 days
200639 days
200745 days
200830 days
200920 days
201026 days
201119 days
201269 days
201337 days
201436 days
201529 days
201620 days
201754 days
201854 days
201922 days
202036 days
202137 days
202243 days
202325 days
202450 days
202532 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

21 years with a frost

Across 21 years with a frost, the median last spring frost at Merchant Valley falls on 11 June and the median first autumn frost on 20 September, which leaves a median of 101 days between them.

Frost dates and growing season at Merchant Valley
MeasureMedian, all yearsEarliest periodRecent period (2004 to 2025)Recent against earliestFitted trend
Last spring frost11 Junen/a11 Junen/an/a
First autumn frost20 Septembern/a20 Septembern/an/a
Growing days101 daysn/a101 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

45 years, 1981 to 2025

A day with at least 40.3 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 99.4 mm (3.9 in) of rain is expected about once in 100 years.

Rainfall return levels at Merchant Valley: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years40.3 mm (1.6 in)
5 years54.1 mm (2.1 in)
10 years64.0 mm (2.5 in)
25 years77.5 mm (3.1 in)
50 years88.2 mm (3.5 in)Longer than the 45 years of record
100 years99.4 mm (3.9 in)Longer than the 45 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, 45 years of values from 1981 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: 116.8 mm (4.6 in) in 1988; 86.4 mm (3.4 in) in 2001; 63.5 mm (2.5 in) in 2024.

Download the Data

  • Data for Merchant Valley standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Merchant Valley 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 (2026-10-12).