(thus leading to dryer starts to more overlap with peak Santa Ana season). I’m curious what Tony’s data has to say.
The driest starts:
1878-79: 0.14 through November
1890-91: 0.25 through November
1891-92: 0.06 through November
1898-99: 0.30 through December
1903-04: 0.57 through January
1912-13: 0.94 through December
1917-18: 0.93 through January
1929-30: 0.32 through December, all of that in September
1932-33: 0.22 through November
1933-34: 0.39 through November
1937-38: 0.01 through November
1938-39: 0.02 through November
1943-44: 0.23 through November
1947-48: 0.30 through November
1948-49: 0.09 through November
1956-57: 0.56 through December
1958-59: 0.52 through December
1959-60: 0.08 through November
1960-61: 0.01 through October, Bel Air Fire started November 6
1962-63: 0.12 through December, 0.64 through January
1971-72: 0.34 through November
1975-76: 0.59 through January, first season I tried skiing
1980-81: 0.00 through November, 0.85 through December
1990-91: 0.21 through December, 1.38 through January
1995-96: 0.11 through November
1999-2000: 0.84 through December
2006-07: 1.43 through January, record low
3.14 for season, Griffith Park Fire in May
2013-14: 0.97 through December
2017-18: 0.19 through December
2020-21: 0.11 through November
2024-25: 0.70 through January, .16 through Jan. 20
So, combined with prior data:
|
Avg | St. Dev. | dry>Nov |
dry>Dec |
dry>Jan |
1877-1900 |
15.68 | 8.52 | 3 | 1 | 0 |
| 1900-1925 |
14.62 | 4.57 | 0 | 1 | 2 |
| 1925-1950 |
15.17 | 5.77 | 7 | 1 | 0 |
| 1950-1975 |
13.86 | 6.48 | 2 | 3 | 0 |
| 1975-2000 |
16.17 | 8.33 | 1 | 2 | 2 |
| 2000-2024 |
13.68 | 8.35 | 1 | 3 | 1 |
| Total |
14.86 | 7.04 | 10% | 7% | 3% |
What the last 3 columns mean:
3% of seasons start with <1.5 inch rain through end of January.
7% of seasons start with <1.0 inch rain through end of December but more than 1.5 by end of January
10% of seasons start with <0.5 inch rain through end of November but more than 1.0 by end of December
I don't see much trend in the dry early seasons. If there is, in terms of fire risk it's surely offset by the retreat of Santa Ana events from September. October is by far the most destructive fire month, includes almost half of those Malibu fires, plus the two largest (Cedar 2003 and Witch 2007) in San Diego, and also Oakland Hills 1991 and Tubbs (Napa/Sonoma) in 2017.