All-time weather records — Portola, CA
Climate change signal in Portola
of Portola's all-time daily heat records were set in the last decade (39 of 366 records since 2015).
of all-time daily cold records were set in the last decade (4 of 366 records since 2015).
If records were spread evenly across the station's history, you'd expect roughly 5% per decade. Decade-by-decade, here's where each record-breaking day was set:
| Decade | Heat records set | # | Cold records set | # |
|---|---|---|---|---|
| 1910s | 29 | 59 | ||
| 1920s | 105 | 115 | ||
| 1930s | 43 | 47 | ||
| 1940s | 22 | 33 | ||
| 1950s | 28 | 30 | ||
| 1960s | 18 | 28 | ||
| 1970s | 16 | 17 | ||
| 1980s | 25 | 10 | ||
| 1990s | 12 | 13 | ||
| 2000s | 19 | 4 | ||
| 2010s | 27 | 9 | ||
| 2020s | 22 | 1 |
Records are the all-time daily extremes that are still standing — each daily record can only be held by one year. The station's earliest hot record was set in 1915, the latest in 2025. Period of observation: 1915-2026.
Records by month
| Month | Hottest day | Coldest day | Wettest day |
|---|---|---|---|
| January | 71.1°F — Jan 25, 1923 | -24.0°F — Jan 1, 1924 | 3.57 in — Jan 21, 1967 |
| February | 72.0°F — Feb 28, 1986 | -20.9°F — Feb 12, 1949 | 2.60 in — Feb 10, 2017 |
| March | 84.0°F — Mar 20, 1926 | -11.9°F — Mar 20, 1952 | 3.61 in — Mar 10, 1995 |
| April | 86.0°F — Apr 30, 1947 | 3.0°F — Apr 13, 1921 | 2.10 in — Apr 8, 2017 |
| May | 93.9°F — May 29, 2003 | 5.0°F — May 8, 1983 | 2.40 in — May 16, 1996 |
| June | 111.0°F — Jun 24, 2006 | 19.9°F — Jun 2, 1929 | 1.12 in — Jun 1, 1961 |
| July | 109.9°F — Jul 1, 1924 | 21.9°F — Jul 1, 1976 | 1.86 in — Jul 11, 2001 |
| August | 107.1°F — Aug 8, 1981 | 19.0°F — Aug 19, 1943 | 2.02 in — Aug 20, 1990 |
| September | 100.0°F — Sep 2, 1955 | 12.0°F — Sep 25, 1929 | 1.10 in — Sep 11, 1976 |
| October | 91.9°F — Oct 1, 1980 | 3.0°F — Oct 29, 1919 | 5.67 in — Oct 25, 2021 |
| November | 82.0°F — Nov 3, 1918 | -6.0°F — Nov 11, 1915 | 2.85 in — Nov 17, 1983 |
| December | 72.0°F — Dec 8, 1921 | -27.9°F — Dec 9, 1972 | 4.18 in — Dec 19, 1955 |
Click a month to see every daily record for that month in Portola.