Annapolis US Naval Academy Aso Weather Records (USW00013752)
Record envelope, standing records and threshold days for Annapolis US Naval Academy Aso (USW00013752), Maryland, United States, with 82 years of record.
Key Facts for Annapolis US Naval Academy Aso
- Annapolis US Naval Academy Aso (USW00013752) is a weather station in Maryland, United States at 38.99 latitude and -76.49 longitude, 2 m (6 ft) above sea level.
- The station reports from 1945 to 2026, 82 years of record.
- 1,464 records set at Annapolis US Naval Academy Aso still stand.
- Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
- Annapolis US Naval Academy Aso tied a daily record high minimum temperature of 22.2 C (72.0 F) on 20 September 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Maryland, United States, 38.99 latitude, -76.49 longitude.
- Elevation: 2 m (6 ft).
- Period of record: 1945 to 2026, 82 years.
- Eligible elements: tmax, tmin, prcp.
Daily Record Envelope and 2026
14 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 25.0 C (77.0 F) | -14.9 C (5.2 F) | 15.6 C (60.1 F) | -11.1 C (12.0 F) |
| Feb | 28.3 C (82.9 F) | -16.1 C (3.0 F) | 12.2 C (54.0 F) | -10.0 C (14.0 F) |
| Mar | 29.4 C (84.9 F) | -9.9 C (14.2 F) | 27.8 C (82.0 F) | -2.8 C (27.0 F) |
| Apr | 32.8 C (91.0 F) | -4.4 C (24.1 F) | 30.6 C (87.1 F) | 2.8 C (37.0 F) |
| May | 34.4 C (93.9 F) | 2.8 C (37.0 F) | 32.2 C (90.0 F) | 6.1 C (43.0 F) |
| Jun | 37.8 C (100.0 F) | 9.4 C (48.9 F) | 35.0 C (95.0 F) | 13.3 C (55.9 F) |
| Jul | 39.4 C (102.9 F) | 15.0 C (59.0 F) | 36.1 C (97.0 F) | 18.3 C (64.9 F) |
| Aug | 38.9 C (102.0 F) | 13.3 C (55.9 F) | 32.8 C (91.0 F) | 17.8 C (64.0 F) |
| Sep | 35.6 C (96.1 F) | 6.7 C (44.1 F) | 33.9 C (93.0 F) | 13.9 C (57.0 F) |
| Oct | 34.4 C (93.9 F) | -1.1 C (30.0 F) | 28.9 C (84.0 F) | 8.3 C (46.9 F) |
| Nov | 27.2 C (81.0 F) | -7.8 C (18.0 F) | n/a | n/a |
| Dec | 23.9 C (75.0 F) | -13.2 C (8.2 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1945 | 50 |
| 1946 | 47 |
| 1947 | 46 |
| 1948 | 38 |
| 1949 | 34 |
| 1950 | 61 |
| 1951 | 48 |
| 1952 | 29 |
| 1953 | 29 |
| 1954 | 34 |
| 1955 | 27 |
| 1956 | 48 |
| 1957 | 45 |
| 1958 | 46 |
| 1959 | 31 |
| 1960 | 40 |
| 1961 | 38 |
| 1962 | 3 |
| 2001 | 11 |
| 2002 | 29 |
| 2003 | 21 |
| 2004 | 36 |
| 2005 | 21 |
| 2006 | 25 |
| 2007 | 26 |
| 2008 | 23 |
| 2009 | 21 |
| 2010 | 29 |
| 2011 | 35 |
| 2012 | 54 |
| 2013 | 22 |
| 2014 | 36 |
| 2015 | 48 |
| 2016 | 41 |
| 2017 | 49 |
| 2018 | 50 |
| 2019 | 47 |
| 2020 | 24 |
| 2021 | 29 |
| 2022 | 26 |
| 2023 | 15 |
| 2024 | 25 |
| 2025 | 11 |
| 2026 | 16 |
Wettest Day of Each Month
Sep: 223.5 mm (8.8 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 56.6 mm (2.2 in) | 9 January 2024 |
| Feb | 56.4 mm (2.2 in) | 22 February 2003 |
| Mar | 61.2 mm (2.4 in) | 20 March 2003 |
| Apr | 68.8 mm (2.7 in) | 15 April 2007 |
| May | 83.3 mm (3.3 in) | 12 May 2008 |
| Jun | 109.5 mm (4.3 in) | 25 June 2006 |
| Jul | 151.6 mm (6.0 in) | 18 July 1945 |
| Aug | 124.7 mm (4.9 in) | 27 August 2011 |
| Sep | 223.5 mm (8.8 in) | 30 September 2010 |
| Oct | 149.1 mm (5.9 in) | 29 October 2012 |
| Nov | 69.6 mm (2.7 in) | 21 November 1952 |
| Dec | 73.7 mm (2.9 in) | 7 December 2011 |
Period of Record Coverage
1945 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1945 | 306 | 84% | No |
| 1946 | 365 | 100% | Yes |
| 1947 | 365 | 100% | Yes |
| 1948 | 366 | 100% | Yes |
| 1949 | 365 | 100% | Yes |
| 1950 | 365 | 100% | Yes |
| 1951 | 365 | 100% | Yes |
| 1952 | 366 | 100% | Yes |
| 1953 | 365 | 100% | Yes |
| 1954 | 365 | 100% | Yes |
| 1955 | 365 | 100% | Yes |
| 1956 | 366 | 100% | Yes |
| 1957 | 365 | 100% | Yes |
| 1958 | 365 | 100% | Yes |
| 1959 | 365 | 100% | Yes |
| 1960 | 366 | 100% | Yes |
| 1961 | 365 | 100% | Yes |
| 1962 | 14 | 4% | No |
| 2001 | 82 | 22% | No |
| 2002 | 365 | 100% | Yes |
| 2003 | 365 | 100% | Yes |
| 2004 | 365 | 100% | Yes |
| 2005 | 365 | 100% | Yes |
| 2006 | 365 | 100% | Yes |
| 2007 | 365 | 100% | Yes |
| 2008 | 366 | 100% | Yes |
| 2009 | 365 | 100% | Yes |
| 2010 | 364 | 100% | Yes |
| 2011 | 365 | 100% | Yes |
| 2012 | 365 | 100% | Yes |
| 2013 | 365 | 100% | Yes |
| 2014 | 365 | 100% | Yes |
| 2015 | 365 | 100% | Yes |
| 2016 | 362 | 99% | Yes |
| 2017 | 365 | 100% | Yes |
| 2018 | 364 | 100% | Yes |
| 2019 | 362 | 99% | Yes |
| 2020 | 366 | 100% | Yes |
| 2021 | 365 | 100% | Yes |
| 2022 | 351 | 96% | Yes |
| 2023 | 358 | 98% | Yes |
| 2024 | 362 | 99% | Yes |
| 2025 | 365 | 100% | Yes |
| 2026 | 283 | 78% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 20 September 2026 | Annapolis US Naval Academy Aso, US | daily high min (Tie, Provisional) | 22.2 C (72.0 F) | tie | 20 years | 3 of 100 (Routine) |
| 10 September 2026 | Annapolis US Naval Academy Aso, US | daily high max (Tie, Provisional) | 31.1 C (88.0 F) | tie | 67 years | 7 of 100 (Routine) |
| 1 September 2026 | Annapolis US Naval Academy Aso, US | daily high max (Provisional) | 33.9 C (93.0 F) | 0.6 C (1.1 F) | 13 years | 13 of 100 (Routine) |
| 6 August 2026 | Annapolis US Naval Academy Aso, US | daily high max (Tie) | 32.2 C (90.0 F) | tie | 71 years | 7 of 100 (Routine) |
| 2 August 2026 | Annapolis US Naval Academy Aso, US | daily rain | 44.2 mm (1.7 in) | 4.8 mm (0.19 in) | 8 years | 12 of 100 (Routine) |
| 16 July 2026 | Annapolis US Naval Academy Aso, US | daily high max | 36.1 C (97.0 F) | 1.7 C (3.1 F) | 72 years | 35 of 100 (Notable) |
| 16 July 2026 | Annapolis US Naval Academy Aso, US | daily high min (Tie) | 26.1 C (79.0 F) | tie | 71 years | 7 of 100 (Routine) |
| 15 July 2026 | Annapolis US Naval Academy Aso, US | daily high max | 36.1 C (97.0 F) | 1.7 C (3.1 F) | 1 year | 14 of 100 (Routine) |
| 3 July 2026 | Annapolis US Naval Academy Aso, US | daily high min | 26.7 C (80.1 F) | 0.6 C (1.1 F) | 8 years | 12 of 100 (Routine) |
| 3 July 2026 | Annapolis US Naval Academy Aso, US | daily high max | 36.1 C (97.0 F) | 0.5 C (0.9 F) | 8 years | 11 of 100 (Routine) |
| 2 July 2026 | Annapolis US Naval Academy Aso, US | daily high min | 26.1 C (79.0 F) | 1.1 C (2.0 F) | 13 years | 16 of 100 (Routine) |
| 12 June 2026 | Annapolis US Naval Academy Aso, US | daily high max | 35.0 C (95.0 F) | 1.7 C (3.1 F) | 68 years | 32 of 100 (Routine) |
| 23 May 2026 | Annapolis US Naval Academy Aso, US | daily low max | 13.9 C (57.0 F) | 0.5 C (0.9 F) | 23 years | 15 of 100 (Routine) |
| 27 April 2026 | Annapolis US Naval Academy Aso, US | daily low min (Tie) | 6.7 C (44.1 F) | tie | 80 years | 8 of 100 (Routine) |
| 17 April 2026 | Annapolis US Naval Academy Aso, US | daily high min | 17.2 C (63.0 F) | 1.1 C (2.0 F) | 24 years | 17 of 100 (Routine) |
| 15 April 2026 | Annapolis US Naval Academy Aso, US | daily high max | 30.6 C (87.1 F) | 0.6 C (1.1 F) | 65 years | 28 of 100 (Routine) |
| 15 April 2026 | Annapolis US Naval Academy Aso, US | daily high min (Tie) | 16.1 C (61.0 F) | tie | 20 years | 3 of 100 (Routine) |
| 1 April 2026 | Annapolis US Naval Academy Aso, US | daily high min | 15.0 C (59.0 F) | 1.7 C (3.1 F) | 9 years | 14 of 100 (Routine) |
| 1 April 2026 | Annapolis US Naval Academy Aso, US | daily high max | 28.9 C (84.0 F) | 1.1 C (2.0 F) | 9 years | 12 of 100 (Routine) |
| 31 March 2026 | Annapolis US Naval Academy Aso, US | daily high min | 17.2 C (63.0 F) | 3.9 C (7.0 F) | 0 years | 17 of 100 (Routine) |
Climate Trend
39 complete years, 1946 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1946 | 13.9 C | -0.24 C |
| 1947 | 12.9 C | -1.16 C |
| 1948 | 13.0 C | -1.06 C |
| 1949 | 14.2 C | +0.13 C |
| 1950 | 12.8 C | -1.30 C |
| 1951 | 13.4 C | -0.69 C |
| 1952 | 13.9 C | -0.24 C |
| 1953 | 14.5 C | +0.40 C |
| 1954 | 13.9 C | -0.23 C |
| 1955 | 13.6 C | -0.45 C |
| 1956 | 13.2 C | -0.87 C |
| 1957 | 13.6 C | -0.52 C |
| 1958 | 12.4 C | -1.71 C |
| 1959 | 14.0 C | -0.05 C |
| 1960 | 13.0 C | -1.07 C |
| 1961 | 13.2 C | -0.87 C |
| 2002 | 14.4 C | +0.28 C |
| 2003 | 13.1 C | -1.04 C |
| 2004 | 14.0 C | -0.13 C |
| 2005 | 13.8 C | -0.29 C |
| 2006 | 14.5 C | +0.38 C |
| 2007 | 14.1 C | +0.04 C |
| 2008 | 14.6 C | +0.51 C |
| 2009 | 13.8 C | -0.34 C |
| 2010 | 14.4 C | +0.29 C |
| 2011 | 15.0 C | +0.88 C |
| 2012 | 16.2 C | +2.11 C |
| 2013 | 13.7 C | -0.43 C |
| 2014 | 13.0 C | -1.12 C |
| 2015 | 14.0 C | -0.11 C |
| 2016 | 14.9 C | +0.84 C |
| 2017 | 15.4 C | +1.26 C |
| 2018 | 15.4 C | +1.32 C |
| 2019 | 15.8 C | +1.68 C |
| 2020 | 14.9 C | +0.83 C |
| 2021 | 14.9 C | +0.84 C |
| 2023 | 15.2 C | +1.15 C |
| 2024 | 15.3 C | +1.25 C |
| 2025 | 14.0 C | -0.08 C |
The annual mean temperature here has risen by 0.2 C (0.1 to 0.3) per decade over 1946 to 2025. In Fahrenheit: 0.3 F (0.2 to 0.5) per decade. The slope is a straight line fitted to 39 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.2 C (0.1 to 0.3) per decade | 0.3 F (0.2 to 0.5) per decade | 1946 to 2025 | 39 | Rise |
| Mean daily maximum | 0.2 C (0.1 to 0.3) per decade | 0.4 F (0.2 to 0.5) per decade | 1946 to 2025 | 39 | Rise |
| Mean daily minimum | 0.2 C (0.1 to 0.2) per decade | 0.3 F (0.2 to 0.4) per decade | 1946 to 2025 | 39 | Rise |
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
1945 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 39.4 C (102.9 F) | 2012 | 35.0 C (95.0 F) | 44 |
| Coldest night (TNn) | -16.1 C (3.0 F) | 1961 | -10.6 C (12.9 F) | 44 |
| Wettest day (Rx1day) | 223.5 mm (8.8 in) | 2010 | 66.9 mm (2.6 in) | 44 |
| Wettest five days (Rx5day) | 270.8 mm (10.7 in) | 2006 | 99.8 mm (3.9 in) | 44 |
| Longest dry spell (CDD) | 39 days | 2024 | 18 days | 44 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1945 | 36.1 C (97.0 F) |
| 1946 | 32.2 C (90.0 F) |
| 1947 | 33.3 C (91.9 F) |
| 1948 | 36.7 C (98.1 F) |
| 1949 | 35.0 C (95.0 F) |
| 1950 | 33.9 C (93.0 F) |
| 1951 | 33.9 C (93.0 F) |
| 1952 | 36.7 C (98.1 F) |
| 1953 | 38.9 C (102.0 F) |
| 1954 | 36.1 C (97.0 F) |
| 1955 | 35.0 C (95.0 F) |
| 1956 | 35.0 C (95.0 F) |
| 1957 | 36.7 C (98.1 F) |
| 1958 | 34.4 C (93.9 F) |
| 1959 | 37.8 C (100.0 F) |
| 1960 | 33.3 C (91.9 F) |
| 1961 | 33.9 C (93.0 F) |
| 1962 | 16.1 C (61.0 F) |
| 2001 | 25.0 C (77.0 F) |
| 2002 | 35.0 C (95.0 F) |
| 2003 | 33.3 C (91.9 F) |
| 2004 | 33.3 C (91.9 F) |
| 2005 | 36.1 C (97.0 F) |
| 2006 | 36.7 C (98.1 F) |
| 2007 | 37.2 C (99.0 F) |
| 2008 | 36.1 C (97.0 F) |
| 2009 | 35.0 C (95.0 F) |
| 2010 | 36.7 C (98.1 F) |
| 2011 | 38.3 C (100.9 F) |
| 2012 | 39.4 C (102.9 F) |
| 2013 | 34.4 C (93.9 F) |
| 2014 | 33.9 C (93.0 F) |
| 2015 | 33.9 C (93.0 F) |
| 2016 | 36.1 C (97.0 F) |
| 2017 | 33.9 C (93.0 F) |
| 2018 | 35.6 C (96.1 F) |
| 2019 | 38.3 C (100.9 F) |
| 2020 | 35.6 C (96.1 F) |
| 2021 | 33.9 C (93.0 F) |
| 2022 | 35.0 C (95.0 F) |
| 2023 | 35.6 C (96.1 F) |
| 2024 | 36.1 C (97.0 F) |
| 2025 | 35.0 C (95.0 F) |
| 2026 | 36.1 C (97.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1945 | -10.0 C (14.0 F) |
| 1946 | -10.6 C (12.9 F) |
| 1947 | -13.3 C (8.1 F) |
| 1948 | -14.4 C (6.1 F) |
| 1949 | -7.8 C (18.0 F) |
| 1950 | -9.4 C (15.1 F) |
| 1951 | -11.1 C (12.0 F) |
| 1952 | -10.0 C (14.0 F) |
| 1953 | -7.2 C (19.0 F) |
| 1954 | -9.4 C (15.1 F) |
| 1955 | -13.3 C (8.1 F) |
| 1956 | -6.7 C (19.9 F) |
| 1957 | -13.3 C (8.1 F) |
| 1958 | -15.0 C (5.0 F) |
| 1959 | -13.3 C (8.1 F) |
| 1960 | -12.8 C (9.0 F) |
| 1961 | -16.1 C (3.0 F) |
| 1962 | -12.8 C (9.0 F) |
| 2001 | -6.1 C (21.0 F) |
| 2002 | -8.3 C (17.1 F) |
| 2003 | -11.1 C (12.0 F) |
| 2004 | -12.2 C (10.0 F) |
| 2005 | -12.2 C (10.0 F) |
| 2006 | -9.4 C (15.1 F) |
| 2007 | -12.2 C (10.0 F) |
| 2008 | -8.2 C (17.2 F) |
| 2009 | -12.1 C (10.2 F) |
| 2010 | -7.7 C (18.1 F) |
| 2011 | -8.8 C (16.2 F) |
| 2012 | -8.2 C (17.2 F) |
| 2013 | -9.3 C (15.3 F) |
| 2014 | -14.9 C (5.2 F) |
| 2015 | -16.0 C (3.2 F) |
| 2016 | -10.6 C (12.9 F) |
| 2017 | -8.8 C (16.2 F) |
| 2018 | -14.3 C (6.3 F) |
| 2019 | -12.2 C (10.0 F) |
| 2020 | -5.5 C (22.1 F) |
| 2021 | -4.3 C (24.3 F) |
| 2022 | -13.2 C (8.2 F) |
| 2023 | -8.8 C (16.2 F) |
| 2024 | -8.8 C (16.2 F) |
| 2025 | -10.5 C (13.1 F) |
| 2026 | -11.1 C (12.0 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1945 | 151.6 mm (6.0 in) |
| 1946 | 35.3 mm (1.4 in) |
| 1947 | 66.3 mm (2.6 in) |
| 1948 | 50.0 mm (2.0 in) |
| 1949 | 48.0 mm (1.9 in) |
| 1950 | 127.0 mm (5.0 in) |
| 1951 | 58.7 mm (2.3 in) |
| 1952 | 72.6 mm (2.9 in) |
| 1953 | 74.9 mm (2.9 in) |
| 1954 | 55.9 mm (2.2 in) |
| 1955 | 91.4 mm (3.6 in) |
| 1956 | 50.5 mm (2.0 in) |
| 1957 | 49.0 mm (1.9 in) |
| 1958 | 84.1 mm (3.3 in) |
| 1959 | 88.4 mm (3.5 in) |
| 1960 | 79.8 mm (3.1 in) |
| 1961 | 41.4 mm (1.6 in) |
| 1962 | 39.1 mm (1.5 in) |
| 2001 | 16.0 mm (0.6 in) |
| 2002 | 60.7 mm (2.4 in) |
| 2003 | 61.2 mm (2.4 in) |
| 2004 | 86.1 mm (3.4 in) |
| 2005 | 82.0 mm (3.2 in) |
| 2006 | 109.5 mm (4.3 in) |
| 2007 | 68.8 mm (2.7 in) |
| 2008 | 83.3 mm (3.3 in) |
| 2009 | 60.2 mm (2.4 in) |
| 2010 | 223.5 mm (8.8 in) |
| 2011 | 124.7 mm (4.9 in) |
| 2012 | 149.1 mm (5.9 in) |
| 2013 | 70.4 mm (2.8 in) |
| 2014 | 83.1 mm (3.3 in) |
| 2015 | 84.8 mm (3.3 in) |
| 2016 | 38.1 mm (1.5 in) |
| 2017 | 46.0 mm (1.8 in) |
| 2018 | 139.7 mm (5.5 in) |
| 2019 | 42.2 mm (1.7 in) |
| 2020 | 97.8 mm (3.9 in) |
| 2021 | 51.8 mm (2.0 in) |
| 2022 | 59.9 mm (2.4 in) |
| 2023 | 61.2 mm (2.4 in) |
| 2024 | 61.7 mm (2.4 in) |
| 2025 | 67.6 mm (2.7 in) |
| 2026 | 44.2 mm (1.7 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1945 | 202.2 mm (8.0 in) |
| 1946 | 59.7 mm (2.4 in) |
| 1947 | 74.9 mm (2.9 in) |
| 1948 | 116.1 mm (4.6 in) |
| 1949 | 67.0 mm (2.6 in) |
| 1950 | 203.3 mm (8.0 in) |
| 1951 | 93.0 mm (3.7 in) |
| 1952 | 128.0 mm (5.0 in) |
| 1953 | 80.2 mm (3.2 in) |
| 1954 | 65.8 mm (2.6 in) |
| 1955 | 137.7 mm (5.4 in) |
| 1956 | 84.1 mm (3.3 in) |
| 1957 | 61.3 mm (2.4 in) |
| 1958 | 113.1 mm (4.5 in) |
| 1959 | 91.7 mm (3.6 in) |
| 1960 | 124.3 mm (4.9 in) |
| 1961 | 81.4 mm (3.2 in) |
| 1962 | 45.4 mm (1.8 in) |
| 2001 | 26.5 mm (1.0 in) |
| 2002 | 121.4 mm (4.8 in) |
| 2003 | 119.5 mm (4.7 in) |
| 2004 | 112.9 mm (4.4 in) |
| 2005 | 132.6 mm (5.2 in) |
| 2006 | 270.8 mm (10.7 in) |
| 2007 | 94.9 mm (3.7 in) |
| 2008 | 193.5 mm (7.6 in) |
| 2009 | 122.2 mm (4.8 in) |
| 2010 | 251.2 mm (9.9 in) |
| 2011 | 150.5 mm (5.9 in) |
| 2012 | 180.4 mm (7.1 in) |
| 2013 | 142.8 mm (5.6 in) |
| 2014 | 95.8 mm (3.8 in) |
| 2015 | 103.8 mm (4.1 in) |
| 2016 | 85.3 mm (3.4 in) |
| 2017 | 74.4 mm (2.9 in) |
| 2018 | 215.9 mm (8.5 in) |
| 2019 | 67.8 mm (2.7 in) |
| 2020 | 150.6 mm (5.9 in) |
| 2021 | 86.1 mm (3.4 in) |
| 2022 | 83.8 mm (3.3 in) |
| 2023 | 71.6 mm (2.8 in) |
| 2024 | 87.1 mm (3.4 in) |
| 2025 | 117.7 mm (4.6 in) |
| 2026 | 65.5 mm (2.6 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1945 | 13 days |
| 1946 | 20 days |
| 1947 | 15 days |
| 1948 | 18 days |
| 1949 | 18 days |
| 1950 | 15 days |
| 1951 | 13 days |
| 1952 | 22 days |
| 1953 | 18 days |
| 1954 | 17 days |
| 1955 | 27 days |
| 1956 | 17 days |
| 1957 | 13 days |
| 1958 | 18 days |
| 1959 | 25 days |
| 1960 | 20 days |
| 1961 | 15 days |
| 1962 | 4 days |
| 2001 | 38 days |
| 2002 | 19 days |
| 2003 | 15 days |
| 2004 | 17 days |
| 2005 | 28 days |
| 2006 | 24 days |
| 2007 | 23 days |
| 2008 | 24 days |
| 2009 | 20 days |
| 2010 | 20 days |
| 2011 | 16 days |
| 2012 | 15 days |
| 2013 | 21 days |
| 2014 | 10 days |
| 2015 | 15 days |
| 2016 | 19 days |
| 2017 | 24 days |
| 2018 | 19 days |
| 2019 | 30 days |
| 2020 | 13 days |
| 2021 | 18 days |
| 2022 | 15 days |
| 2023 | 20 days |
| 2024 | 39 days |
| 2025 | 16 days |
| 2026 | 20 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
39 years with a frostAcross 39 years with a frost, the median last spring frost at Annapolis US Naval Academy Aso falls on 23 March and the median first autumn frost on 19 November, which leaves a median of 242 days between them.
Fitted over all years, the growing season changes by +1.9 days per decade at this station.
| Measure | Median, all years | Earliest period | Recent period (1955 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 23 March | n/a | 23 March | n/a | -1.1 days per decade |
| First autumn frost | 19 November | n/a | 20 November | n/a | +0.8 days per decade |
| Growing days | 242 days | n/a | 244 days | n/a | +1.9 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
40 years, 1946 to 2025A day with at least 67.7 mm (2.7 in) of rain is expected about once in 2 years. A day with at least 220.5 mm (8.7 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 67.7 mm (2.7 in) | |
| 5 years | 95.9 mm (3.8 in) | |
| 10 years | 118.9 mm (4.7 in) | |
| 25 years | 153.7 mm (6.1 in) | |
| 50 years | 184.7 mm (7.3 in) | Longer than the 40 years of record |
| 100 years | 220.5 mm (8.7 in) | Longer than the 40 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, 40 years of values from 1946 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: 223.5 mm (8.8 in) in 2010; 149.1 mm (5.9 in) in 2012; 139.7 mm (5.5 in) in 2018.
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).