Tiber Dam Weather Records (USC00248233)
Record envelope, standing records and threshold days for Tiber Dam (USC00248233), Montana, United States, with 75 years of record.
Key Facts for Tiber Dam
- Tiber Dam (USC00248233) is a weather station in Montana, United States at 48.31 latitude and -111.09 longitude, 887 m (2,909 ft) above sea level.
- The station reports from 1952 to 2026, 75 years of record.
- 1,464 records set at Tiber Dam still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Tiber Dam set a daily record low maximum temperature of 17.8 C (64.0 F) on 15 August 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Montana, United States, 48.31 latitude, -111.09 longitude.
- Elevation: 887 m (2,909 ft).
- Period of record: 1952 to 2026, 75 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
18 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 21.1 C (70.0 F) | -47.2 C (-53.0 F) | 17.2 C (63.0 F) | -25.6 C (-14.1 F) |
| Feb | 23.3 C (73.9 F) | -40.0 C (-40.0 F) | 21.1 C (70.0 F) | -24.4 C (-11.9 F) |
| Mar | 27.2 C (81.0 F) | -35.6 C (-32.1 F) | 23.3 C (73.9 F) | -21.1 C (-6.0 F) |
| Apr | 31.7 C (89.1 F) | -25.0 C (-13.0 F) | 27.8 C (82.0 F) | -9.4 C (15.1 F) |
| May | 35.0 C (95.0 F) | -10.0 C (14.0 F) | 34.4 C (93.9 F) | -6.7 C (19.9 F) |
| Jun | 39.4 C (102.9 F) | -1.1 C (30.0 F) | 28.3 C (82.9 F) | 3.9 C (39.0 F) |
| Jul | 41.7 C (107.1 F) | 2.2 C (36.0 F) | 40.6 C (105.1 F) | 8.9 C (48.0 F) |
| Aug | 41.7 C (107.1 F) | -1.7 C (28.9 F) | 40.6 C (105.1 F) | 4.4 C (39.9 F) |
| Sep | 37.2 C (99.0 F) | -8.9 C (16.0 F) | 31.1 C (88.0 F) | -1.1 C (30.0 F) |
| Oct | 34.4 C (93.9 F) | -25.0 C (-13.0 F) | 27.8 C (82.0 F) | 2.2 C (36.0 F) |
| Nov | 25.6 C (78.1 F) | -33.3 C (-27.9 F) | n/a | n/a |
| Dec | 20.0 C (68.0 F) | -42.8 C (-45.0 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1952 | 1 |
| 1953 | 18 |
| 1954 | 56 |
| 1955 | 30 |
| 1956 | 18 |
| 1957 | 28 |
| 1958 | 14 |
| 1959 | 30 |
| 1960 | 24 |
| 1961 | 31 |
| 1962 | 29 |
| 1963 | 23 |
| 1964 | 18 |
| 1965 | 39 |
| 1966 | 24 |
| 1967 | 34 |
| 1968 | 24 |
| 1969 | 35 |
| 1970 | 10 |
| 1971 | 21 |
| 1972 | 29 |
| 1973 | 28 |
| 1974 | 13 |
| 1975 | 17 |
| 1976 | 11 |
| 1977 | 21 |
| 1978 | 10 |
| 1979 | 18 |
| 1980 | 17 |
| 1981 | 19 |
| 1982 | 32 |
| 1983 | 27 |
| 1984 | 28 |
| 1985 | 37 |
| 1986 | 19 |
| 1987 | 35 |
| 1988 | 36 |
| 1989 | 21 |
| 1990 | 32 |
| 1991 | 26 |
| 1992 | 44 |
| 1993 | 13 |
| 1994 | 15 |
| 1995 | 10 |
| 1996 | 22 |
| 1997 | 14 |
| 1998 | 7 |
| 1999 | 16 |
| 2000 | 15 |
| 2001 | 8 |
| 2002 | 39 |
| 2003 | 25 |
| 2004 | 15 |
| 2005 | 19 |
| 2006 | 13 |
| 2007 | 24 |
| 2008 | 16 |
| 2009 | 29 |
| 2010 | 10 |
| 2011 | 13 |
| 2012 | 22 |
| 2013 | 12 |
| 2023 | 13 |
| 2024 | 13 |
| 2025 | 30 |
| 2026 | 24 |
All-Time Record Progression
2 new records| Date | Kind | Detail |
|---|---|---|
| 1990-08-17 | Record high minimum temperature | Record high minimum temperature 23.9 C (75.0 F) |
| 1999-06-03 | Record daily precipitation | Record daily precipitation 105.4 mm (4.1 in) |
Wettest Day of Each Month
Jun: 105.4 mm (4.1 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 22.1 mm (0.9 in) | 15 January 2006 |
| Feb | 8.1 mm (0.32 in) | 26 February 1954 |
| Mar | 38.4 mm (1.5 in) | 30 March 1981 |
| Apr | 28.4 mm (1.1 in) | 17 April 1978 |
| May | 34.3 mm (1.4 in) | 25 May 1980 |
| Jun | 105.4 mm (4.1 in) | 3 June 1999 |
| Jul | 48.3 mm (1.9 in) | 31 July 2001 |
| Aug | 58.7 mm (2.3 in) | 15 August 1968 |
| Sep | 41.4 mm (1.6 in) | 18 September 2024 |
| Oct | 26.4 mm (1.0 in) | 31 October 1992 |
| Nov | 13.2 mm (0.5 in) | 7 November 1997 |
| Dec | 12.4 mm (0.5 in) | 2 December 1972 |
Period of Record Coverage
1952 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1952 | 48 | 13% | No |
| 1953 | 363 | 99% | Yes |
| 1954 | 365 | 100% | Yes |
| 1955 | 365 | 100% | Yes |
| 1956 | 365 | 100% | Yes |
| 1957 | 364 | 100% | Yes |
| 1958 | 364 | 100% | Yes |
| 1959 | 364 | 100% | Yes |
| 1960 | 366 | 100% | Yes |
| 1961 | 364 | 100% | Yes |
| 1962 | 356 | 98% | Yes |
| 1963 | 365 | 100% | Yes |
| 1964 | 366 | 100% | Yes |
| 1965 | 365 | 100% | Yes |
| 1966 | 364 | 100% | Yes |
| 1967 | 365 | 100% | Yes |
| 1968 | 365 | 100% | Yes |
| 1969 | 364 | 100% | Yes |
| 1970 | 362 | 99% | Yes |
| 1971 | 363 | 99% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 362 | 99% | Yes |
| 1974 | 364 | 100% | Yes |
| 1975 | 360 | 99% | Yes |
| 1976 | 346 | 95% | Yes |
| 1977 | 362 | 99% | Yes |
| 1978 | 361 | 99% | Yes |
| 1979 | 355 | 97% | Yes |
| 1980 | 365 | 100% | Yes |
| 1981 | 362 | 99% | Yes |
| 1982 | 348 | 95% | Yes |
| 1983 | 343 | 94% | Yes |
| 1984 | 332 | 91% | Yes |
| 1985 | 319 | 87% | No |
| 1986 | 331 | 91% | Yes |
| 1987 | 329 | 90% | Yes |
| 1988 | 323 | 88% | No |
| 1989 | 304 | 83% | No |
| 1990 | 330 | 90% | Yes |
| 1991 | 280 | 77% | No |
| 1992 | 271 | 74% | No |
| 1993 | 218 | 60% | No |
| 1994 | 270 | 74% | No |
| 1995 | 301 | 82% | No |
| 1996 | 323 | 88% | No |
| 1997 | 243 | 67% | No |
| 1998 | 208 | 57% | No |
| 1999 | 302 | 83% | No |
| 2000 | 320 | 87% | No |
| 2001 | 315 | 86% | No |
| 2002 | 310 | 85% | No |
| 2003 | 293 | 80% | No |
| 2004 | 306 | 84% | No |
| 2005 | 324 | 89% | No |
| 2006 | 329 | 90% | Yes |
| 2007 | 323 | 88% | No |
| 2008 | 349 | 95% | Yes |
| 2009 | 361 | 99% | Yes |
| 2010 | 352 | 96% | Yes |
| 2011 | 357 | 98% | Yes |
| 2012 | 364 | 99% | Yes |
| 2013 | 351 | 96% | Yes |
| 2023 | 126 | 35% | No |
| 2024 | 352 | 96% | Yes |
| 2025 | 365 | 100% | Yes |
| 2026 | 248 | 68% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 15 August 2026 | Tiber Dam, US | daily low max (Provisional) | 17.8 C (64.0 F) | 1.6 C (2.9 F) | 13 years | 14 of 100 (Routine) |
| 5 August 2026 | Tiber Dam, US | daily low min | 4.4 C (39.9 F) | 0.6 C (1.1 F) | 48 years | 22 of 100 (Routine) |
| 2 August 2026 | Tiber Dam, US | daily high max | 40.6 C (105.1 F) | 2.8 C (5.0 F) | 55 years | 29 of 100 (Routine) |
| 26 July 2026 | Tiber Dam, US | daily high max | 40.6 C (105.1 F) | 3.4 C (6.1 F) | 32 years | 23 of 100 (Routine) |
| 2 June 2026 | Tiber Dam, US | daily low max | 9.4 C (48.9 F) | 4.5 C (8.1 F) | 20 years | 21 of 100 (Routine) |
| 1 June 2026 | Tiber Dam, US | daily low max | 9.4 C (48.9 F) | 5.6 C (10.1 F) | 55 years | 34 of 100 (Routine) |
| 29 May 2026 | Tiber Dam, US | monthly high min | 17.2 C (63.0 F) | 1.6 C (2.9 F) | 68 years | 41 of 100 (Notable) |
| 29 May 2026 | Tiber Dam, US | daily high max (Tie) | 33.3 C (91.9 F) | tie | 41 years | 4 of 100 (Routine) |
| 28 May 2026 | Tiber Dam, US | daily high min (Tie) | 14.4 C (57.9 F) | tie | 40 years | 4 of 100 (Routine) |
| 27 May 2026 | Tiber Dam, US | daily high max | 34.4 C (93.9 F) | 0.5 C (0.9 F) | 60 years | 25 of 100 (Routine) |
| 18 May 2026 | Tiber Dam, US | daily low max | 6.7 C (44.1 F) | 4.4 C (7.9 F) | 48 years | 28 of 100 (Routine) |
| 14 May 2026 | Tiber Dam, US | daily high max | 32.2 C (90.0 F) | 2.8 C (5.0 F) | 41 years | 23 of 100 (Routine) |
| 7 May 2026 | Tiber Dam, US | daily low min | -6.7 C (19.9 F) | 3.4 C (6.1 F) | 41 years | 27 of 100 (Routine) |
| 25 April 2026 | Tiber Dam, US | daily low max | 1.7 C (35.1 F) | 0.5 C (0.9 F) | 65 years | 26 of 100 (Routine) |
| 22 April 2026 | Tiber Dam, US | daily high max | 27.8 C (82.0 F) | 0.6 C (1.1 F) | 56 years | 24 of 100 (Routine) |
| 21 March 2026 | Tiber Dam, US | daily high max | 23.3 C (73.9 F) | 2.7 C (4.9 F) | 65 years | 29 of 100 (Routine) |
| 21 March 2026 | Tiber Dam, US | daily high min | 2.2 C (36.0 F) | 0.5 C (0.9 F) | 31 years | 16 of 100 (Routine) |
| 18 March 2026 | Tiber Dam, US | daily high min | 6.1 C (43.0 F) | 2.8 C (5.0 F) | 19 years | 16 of 100 (Routine) |
| 27 February 2026 | Tiber Dam, US | daily high min (Tie) | 1.1 C (34.0 F) | tie | 68 years | 6 of 100 (Routine) |
| 17 February 2026 | Tiber Dam, US | daily high max | 15.6 C (60.1 F) | 1.7 C (3.1 F) | 72 years | 29 of 100 (Routine) |
Climate Trend
42 complete years, 1953 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1953 | 8.2 C | +1.42 C |
| 1954 | 6.6 C | -0.10 C |
| 1955 | 4.6 C | -2.12 C |
| 1956 | 6.7 C | -0.06 C |
| 1957 | 6.7 C | -0.07 C |
| 1958 | 7.3 C | +0.57 C |
| 1959 | 5.9 C | -0.89 C |
| 1960 | 6.7 C | +0.00 C |
| 1961 | 7.6 C | +0.89 C |
| 1962 | 7.0 C | +0.27 C |
| 1963 | 7.7 C | +0.98 C |
| 1964 | 6.3 C | -0.42 C |
| 1965 | 5.2 C | -1.50 C |
| 1966 | 5.9 C | -0.82 C |
| 1967 | 7.0 C | +0.21 C |
| 1968 | 6.6 C | -0.17 C |
| 1969 | 5.6 C | -1.14 C |
| 1970 | 6.0 C | -0.75 C |
| 1971 | 6.4 C | -0.37 C |
| 1972 | 5.7 C | -1.05 C |
| 1973 | 7.8 C | +1.01 C |
| 1974 | 8.0 C | +1.30 C |
| 1975 | 5.5 C | -1.21 C |
| 1977 | 6.9 C | +0.15 C |
| 1978 | 4.8 C | -1.94 C |
| 1979 | 6.3 C | -0.43 C |
| 1980 | 7.0 C | +0.25 C |
| 1981 | 8.5 C | +1.79 C |
| 1982 | 5.0 C | -1.72 C |
| 1983 | 6.9 C | +0.13 C |
| 1984 | 7.3 C | +0.55 C |
| 1985 | 5.9 C | -0.81 C |
| 1986 | 7.9 C | +1.20 C |
| 1987 | 9.5 C | +2.76 C |
| 1988 | 8.8 C | +2.09 C |
| 2008 | 6.6 C | -0.16 C |
| 2009 | 6.2 C | -0.53 C |
| 2010 | 5.7 C | -1.00 C |
| 2011 | 6.3 C | -0.43 C |
| 2012 | 8.1 C | +1.36 C |
| 2013 | 7.4 C | +0.61 C |
| 2025 | 6.8 C | +0.09 C |
The fitted trend in annual mean temperature here over 1953 to 2025 is 0.1 C (-0.1 to 0.3) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.2 to 0.5) per decade. The slope is a straight line fitted to 42 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.1 C (-0.1 to 0.3) per decade | 0.1 F (-0.2 to 0.5) per decade | 1953 to 2025 | 42 | Not clearly different from zero |
| Mean daily maximum | 0.00 C (-0.23 to 0.22) per decade | -0.01 F (-0.41 to 0.40) per decade | 1953 to 2025 | 42 | Not clearly different from zero |
| Mean daily minimum | 0.14 C (-0.02 to 0.30) per decade | 0.25 F (-0.03 to 0.54) per decade | 1953 to 2025 | 42 | Not clearly different from zero |
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
1952 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 41.7 C (107.1 F) | 1961 | 37.2 C (99.0 F) | 66 |
| Coldest night (TNn) | -47.2 C (-53.0 F) | 1954 | -33.3 C (-27.9 F) | 66 |
| Wettest day (Rx1day) | 105.4 mm (4.1 in) | 1999 | 26.6 mm (1.0 in) | 66 |
| Wettest five days (Rx5day) | 123.2 mm (4.9 in) | 1999 | 41.1 mm (1.6 in) | 66 |
| Longest dry spell (CDD) | 88 days | 1987 | 46 days | 66 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1952 | 15.0 C (59.0 F) |
| 1953 | 39.4 C (102.9 F) |
| 1954 | 36.1 C (97.0 F) |
| 1955 | 35.6 C (96.1 F) |
| 1956 | 36.1 C (97.0 F) |
| 1957 | 36.7 C (98.1 F) |
| 1958 | 37.2 C (99.0 F) |
| 1959 | 37.2 C (99.0 F) |
| 1960 | 40.6 C (105.1 F) |
| 1961 | 41.7 C (107.1 F) |
| 1962 | 35.6 C (96.1 F) |
| 1963 | 37.8 C (100.0 F) |
| 1964 | 37.8 C (100.0 F) |
| 1965 | 36.1 C (97.0 F) |
| 1966 | 35.6 C (96.1 F) |
| 1967 | 37.2 C (99.0 F) |
| 1968 | 37.2 C (99.0 F) |
| 1969 | 40.6 C (105.1 F) |
| 1970 | 37.2 C (99.0 F) |
| 1971 | 38.9 C (102.0 F) |
| 1972 | 36.7 C (98.1 F) |
| 1973 | 38.9 C (102.0 F) |
| 1974 | 36.7 C (98.1 F) |
| 1975 | 38.3 C (100.9 F) |
| 1976 | 36.1 C (97.0 F) |
| 1977 | 36.1 C (97.0 F) |
| 1978 | 35.6 C (96.1 F) |
| 1979 | 38.3 C (100.9 F) |
| 1980 | 36.7 C (98.1 F) |
| 1981 | 37.2 C (99.0 F) |
| 1982 | 35.0 C (95.0 F) |
| 1983 | 41.1 C (106.0 F) |
| 1984 | 38.9 C (102.0 F) |
| 1985 | 38.9 C (102.0 F) |
| 1986 | 36.7 C (98.1 F) |
| 1987 | 36.7 C (98.1 F) |
| 1988 | 37.2 C (99.0 F) |
| 1989 | 35.0 C (95.0 F) |
| 1990 | 39.4 C (102.9 F) |
| 1991 | 38.3 C (100.9 F) |
| 1992 | 36.7 C (98.1 F) |
| 1993 | 33.3 C (91.9 F) |
| 1994 | 38.3 C (100.9 F) |
| 1995 | 33.3 C (91.9 F) |
| 1996 | 37.8 C (100.0 F) |
| 1997 | 37.2 C (99.0 F) |
| 1998 | 37.2 C (99.0 F) |
| 1999 | 38.3 C (100.9 F) |
| 2000 | 38.9 C (102.0 F) |
| 2001 | 38.3 C (100.9 F) |
| 2002 | 36.7 C (98.1 F) |
| 2003 | 38.3 C (100.9 F) |
| 2004 | 37.8 C (100.0 F) |
| 2005 | 36.7 C (98.1 F) |
| 2006 | 36.1 C (97.0 F) |
| 2007 | 41.1 C (106.0 F) |
| 2008 | 36.1 C (97.0 F) |
| 2009 | 35.0 C (95.0 F) |
| 2010 | 37.8 C (100.0 F) |
| 2011 | 38.9 C (102.0 F) |
| 2012 | 37.2 C (99.0 F) |
| 2013 | 36.7 C (98.1 F) |
| 2023 | 36.1 C (97.0 F) |
| 2024 | 41.7 C (107.1 F) |
| 2025 | 35.6 C (96.1 F) |
| 2026 | 40.6 C (105.1 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1952 | -22.2 C (-8.0 F) |
| 1953 | -23.9 C (-11.0 F) |
| 1954 | -47.2 C (-53.0 F) |
| 1955 | -32.8 C (-27.0 F) |
| 1956 | -36.1 C (-33.0 F) |
| 1957 | -40.6 C (-41.1 F) |
| 1958 | -27.8 C (-18.0 F) |
| 1959 | -32.2 C (-26.0 F) |
| 1960 | -35.6 C (-32.1 F) |
| 1961 | -35.6 C (-32.1 F) |
| 1962 | -37.8 C (-36.0 F) |
| 1963 | -34.4 C (-29.9 F) |
| 1964 | -35.0 C (-31.0 F) |
| 1965 | -28.3 C (-18.9 F) |
| 1966 | -33.3 C (-27.9 F) |
| 1967 | -31.7 C (-25.1 F) |
| 1968 | -42.8 C (-45.0 F) |
| 1969 | -40.6 C (-41.1 F) |
| 1970 | -31.1 C (-24.0 F) |
| 1971 | -33.3 C (-27.9 F) |
| 1972 | -39.4 C (-38.9 F) |
| 1973 | -27.2 C (-17.0 F) |
| 1974 | -36.1 C (-33.0 F) |
| 1975 | -31.7 C (-25.1 F) |
| 1976 | -29.4 C (-20.9 F) |
| 1977 | -36.7 C (-34.1 F) |
| 1978 | -35.6 C (-32.1 F) |
| 1979 | -41.1 C (-42.0 F) |
| 1980 | -32.2 C (-26.0 F) |
| 1981 | -30.6 C (-23.1 F) |
| 1982 | -41.1 C (-42.0 F) |
| 1983 | -41.7 C (-43.1 F) |
| 1984 | -34.4 C (-29.9 F) |
| 1985 | -34.4 C (-29.9 F) |
| 1986 | -33.3 C (-27.9 F) |
| 1987 | -25.0 C (-13.0 F) |
| 1988 | -27.8 C (-18.0 F) |
| 1989 | -37.8 C (-36.0 F) |
| 1990 | -30.6 C (-23.1 F) |
| 1991 | -32.8 C (-27.0 F) |
| 1992 | -35.0 C (-31.0 F) |
| 1993 | -32.8 C (-27.0 F) |
| 1994 | -40.0 C (-40.0 F) |
| 1995 | -29.4 C (-20.9 F) |
| 1996 | -38.9 C (-38.0 F) |
| 1997 | -39.4 C (-38.9 F) |
| 1998 | -36.1 C (-33.0 F) |
| 1999 | -27.2 C (-17.0 F) |
| 2000 | -31.1 C (-24.0 F) |
| 2001 | -28.9 C (-20.0 F) |
| 2002 | -32.8 C (-27.0 F) |
| 2003 | -32.8 C (-27.0 F) |
| 2004 | -32.8 C (-27.0 F) |
| 2005 | -36.1 C (-33.0 F) |
| 2006 | -32.8 C (-27.0 F) |
| 2007 | -26.1 C (-15.0 F) |
| 2008 | -33.3 C (-27.9 F) |
| 2009 | -33.9 C (-29.0 F) |
| 2010 | -33.3 C (-27.9 F) |
| 2011 | -34.4 C (-29.9 F) |
| 2012 | -31.1 C (-24.0 F) |
| 2013 | -37.2 C (-35.0 F) |
| 2023 | -17.2 C (1.0 F) |
| 2024 | -40.0 C (-40.0 F) |
| 2025 | -36.1 C (-33.0 F) |
| 2026 | -25.6 C (-14.1 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1952 | 1.5 mm (0.06 in) |
| 1953 | 34.8 mm (1.4 in) |
| 1954 | 27.9 mm (1.1 in) |
| 1955 | 31.2 mm (1.2 in) |
| 1956 | 17.0 mm (0.7 in) |
| 1957 | 24.4 mm (1.0 in) |
| 1958 | 35.3 mm (1.4 in) |
| 1959 | 50.8 mm (2.0 in) |
| 1960 | 18.8 mm (0.7 in) |
| 1961 | 22.4 mm (0.9 in) |
| 1962 | 23.6 mm (0.9 in) |
| 1963 | 17.8 mm (0.7 in) |
| 1964 | 41.1 mm (1.6 in) |
| 1965 | 27.9 mm (1.1 in) |
| 1966 | 36.8 mm (1.4 in) |
| 1967 | 20.6 mm (0.8 in) |
| 1968 | 58.7 mm (2.3 in) |
| 1969 | 25.9 mm (1.0 in) |
| 1970 | 45.0 mm (1.8 in) |
| 1971 | 23.4 mm (0.9 in) |
| 1972 | 24.6 mm (1.0 in) |
| 1973 | 20.3 mm (0.8 in) |
| 1974 | 26.9 mm (1.1 in) |
| 1975 | 40.9 mm (1.6 in) |
| 1976 | 18.0 mm (0.7 in) |
| 1977 | 17.3 mm (0.7 in) |
| 1978 | 28.4 mm (1.1 in) |
| 1979 | 15.2 mm (0.6 in) |
| 1980 | 34.3 mm (1.4 in) |
| 1981 | 38.4 mm (1.5 in) |
| 1982 | 52.1 mm (2.1 in) |
| 1983 | 26.2 mm (1.0 in) |
| 1984 | 20.1 mm (0.8 in) |
| 1985 | 24.9 mm (1.0 in) |
| 1986 | 33.0 mm (1.3 in) |
| 1987 | 26.9 mm (1.1 in) |
| 1988 | 36.1 mm (1.4 in) |
| 1989 | 26.7 mm (1.1 in) |
| 1990 | 35.1 mm (1.4 in) |
| 1991 | 48.8 mm (1.9 in) |
| 1992 | 26.4 mm (1.0 in) |
| 1993 | 28.4 mm (1.1 in) |
| 1994 | 17.5 mm (0.7 in) |
| 1995 | 51.8 mm (2.0 in) |
| 1996 | 30.7 mm (1.2 in) |
| 1997 | 19.1 mm (0.8 in) |
| 1998 | 24.4 mm (1.0 in) |
| 1999 | 105.4 mm (4.1 in) |
| 2000 | 33.5 mm (1.3 in) |
| 2001 | 48.3 mm (1.9 in) |
| 2002 | 43.9 mm (1.7 in) |
| 2003 | 25.9 mm (1.0 in) |
| 2004 | 31.5 mm (1.2 in) |
| 2005 | 20.8 mm (0.8 in) |
| 2006 | 22.1 mm (0.9 in) |
| 2007 | 18.5 mm (0.7 in) |
| 2008 | 26.4 mm (1.0 in) |
| 2009 | 24.6 mm (1.0 in) |
| 2010 | 25.4 mm (1.0 in) |
| 2011 | 15.5 mm (0.6 in) |
| 2012 | 25.4 mm (1.0 in) |
| 2013 | 44.7 mm (1.8 in) |
| 2023 | 14.0 mm (0.6 in) |
| 2024 | 41.4 mm (1.6 in) |
| 2025 | 53.8 mm (2.1 in) |
| 2026 | 16.0 mm (0.6 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1952 | 2.3 mm (0.09 in) |
| 1953 | 79.7 mm (3.1 in) |
| 1954 | 40.9 mm (1.6 in) |
| 1955 | 62.4 mm (2.5 in) |
| 1956 | 27.2 mm (1.1 in) |
| 1957 | 31.5 mm (1.2 in) |
| 1958 | 58.7 mm (2.3 in) |
| 1959 | 81.8 mm (3.2 in) |
| 1960 | 32.0 mm (1.3 in) |
| 1961 | 34.8 mm (1.4 in) |
| 1962 | 27.4 mm (1.1 in) |
| 1963 | 25.9 mm (1.0 in) |
| 1964 | 51.3 mm (2.0 in) |
| 1965 | 62.5 mm (2.5 in) |
| 1966 | 54.6 mm (2.1 in) |
| 1967 | 27.5 mm (1.1 in) |
| 1968 | 76.2 mm (3.0 in) |
| 1969 | 53.9 mm (2.1 in) |
| 1970 | 77.2 mm (3.0 in) |
| 1971 | 26.0 mm (1.0 in) |
| 1972 | 29.0 mm (1.1 in) |
| 1973 | 32.5 mm (1.3 in) |
| 1974 | 44.2 mm (1.7 in) |
| 1975 | 64.4 mm (2.5 in) |
| 1976 | 33.0 mm (1.3 in) |
| 1977 | 31.7 mm (1.2 in) |
| 1978 | 48.0 mm (1.9 in) |
| 1979 | 24.8 mm (1.0 in) |
| 1980 | 48.0 mm (1.9 in) |
| 1981 | 49.9 mm (2.0 in) |
| 1982 | 75.2 mm (3.0 in) |
| 1983 | 29.2 mm (1.1 in) |
| 1984 | 28.7 mm (1.1 in) |
| 1985 | 37.6 mm (1.5 in) |
| 1986 | 37.9 mm (1.5 in) |
| 1987 | 49.0 mm (1.9 in) |
| 1988 | 42.2 mm (1.7 in) |
| 1989 | 44.0 mm (1.7 in) |
| 1990 | 46.9 mm (1.8 in) |
| 1991 | 83.4 mm (3.3 in) |
| 1992 | 40.9 mm (1.6 in) |
| 1993 | 53.6 mm (2.1 in) |
| 1994 | 36.1 mm (1.4 in) |
| 1995 | 85.3 mm (3.4 in) |
| 1996 | 35.2 mm (1.4 in) |
| 1997 | 43.4 mm (1.7 in) |
| 1998 | 29.5 mm (1.2 in) |
| 1999 | 123.2 mm (4.9 in) |
| 2000 | 39.9 mm (1.6 in) |
| 2001 | 48.3 mm (1.9 in) |
| 2002 | 77.9 mm (3.1 in) |
| 2003 | 25.9 mm (1.0 in) |
| 2004 | 32.8 mm (1.3 in) |
| 2005 | 59.2 mm (2.3 in) |
| 2006 | 25.5 mm (1.0 in) |
| 2007 | 28.4 mm (1.1 in) |
| 2008 | 46.5 mm (1.8 in) |
| 2009 | 41.2 mm (1.6 in) |
| 2010 | 38.1 mm (1.5 in) |
| 2011 | 39.9 mm (1.6 in) |
| 2012 | 37.3 mm (1.5 in) |
| 2013 | 50.5 mm (2.0 in) |
| 2023 | 28.3 mm (1.1 in) |
| 2024 | 57.1 mm (2.2 in) |
| 2025 | 54.3 mm (2.1 in) |
| 2026 | 33.5 mm (1.3 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1952 | 38 days |
| 1953 | 73 days |
| 1954 | 68 days |
| 1955 | 55 days |
| 1956 | 63 days |
| 1957 | 46 days |
| 1958 | 36 days |
| 1959 | 52 days |
| 1960 | 70 days |
| 1961 | 41 days |
| 1962 | 40 days |
| 1963 | 30 days |
| 1964 | 52 days |
| 1965 | 62 days |
| 1966 | 35 days |
| 1967 | 54 days |
| 1968 | 53 days |
| 1969 | 73 days |
| 1970 | 31 days |
| 1971 | 50 days |
| 1972 | 33 days |
| 1973 | 53 days |
| 1974 | 35 days |
| 1975 | 38 days |
| 1976 | 36 days |
| 1977 | 41 days |
| 1978 | 36 days |
| 1979 | 34 days |
| 1980 | 26 days |
| 1981 | 24 days |
| 1982 | 40 days |
| 1983 | 37 days |
| 1984 | 59 days |
| 1985 | 31 days |
| 1986 | 29 days |
| 1987 | 88 days |
| 1988 | 60 days |
| 1989 | 25 days |
| 1990 | 69 days |
| 1991 | 50 days |
| 1992 | 46 days |
| 1993 | 29 days |
| 1994 | 41 days |
| 1995 | 61 days |
| 1996 | 28 days |
| 1997 | 53 days |
| 1998 | 62 days |
| 1999 | 37 days |
| 2000 | 20 days |
| 2001 | 81 days |
| 2002 | 71 days |
| 2003 | 53 days |
| 2004 | 51 days |
| 2005 | 58 days |
| 2006 | 35 days |
| 2007 | 75 days |
| 2008 | 48 days |
| 2009 | 43 days |
| 2010 | 52 days |
| 2011 | 27 days |
| 2012 | 47 days |
| 2013 | 46 days |
| 2023 | 56 days |
| 2024 | 69 days |
| 2025 | 29 days |
| 2026 | 44 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
42 years with a frostAcross 42 years with a frost, the median last spring frost at Tiber Dam falls on 18 May and the median first autumn frost on 18 September, which leaves a median of 123 days between them.
Fitted over all years, the growing season changes by +2.1 days per decade at this station.
| Measure | Median, all years | Earliest period | Recent period (1965 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 18 May | n/a | 20 May | n/a | +0.2 days per decade |
| First autumn frost | 18 September | n/a | 19 September | n/a | +2.3 days per decade |
| Growing days | 123 days | n/a | 125 days | n/a | +2.1 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
55 years, 1953 to 2010A day with at least 27.9 mm (1.1 in) of rain is expected about once in 2 years. A day with at least 87.5 mm (3.4 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 27.9 mm (1.1 in) | |
| 5 years | 38.7 mm (1.5 in) | |
| 10 years | 47.6 mm (1.9 in) | |
| 25 years | 61.2 mm (2.4 in) | |
| 50 years | 73.4 mm (2.9 in) | |
| 100 years | 87.5 mm (3.4 in) | Longer than the 55 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, 55 years of values from 1953 to 2010.
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: 105.4 mm (4.1 in) in 1999; 58.7 mm (2.3 in) in 1968; 52.1 mm (2.1 in) in 1982.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
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 2026-10-13 (13 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-13).