United States · 1991–2020

Best time to visit
Napa Soda Springs.

May leads for comfortable weather in Napa Soda Springs: typically 24.6°C by day, 9.9°C at night, with 27 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortMay
Typical high24.6°C
Typical low9.9°C
Rain in May27 mm
Comfort

May

May · October · June

89climate match
Beach

July

July · August · September

76climate match
Outdoors

May

May · April · October

86climate match

The weakest month is December, scoring 30 against May’s 89days reach only 14.6°C, 9° below the 24°C the score treats as ideal, and nights drop to 4.3°C.

Month by month

The whole year,
without the guesswork.

The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.

Jan
3114.7° / 4.6°
Feb
4117.2° / 5.4°
Mar
5519.6° / 6.4°
Apr
7722.2° / 7.5°
May
8924.6° / 9.9°
Jun
8227.8° / 12°
Jul
8228.3° / 13°
Aug
8128.6° / 13°
Sep
7828.9° / 11.9°
Oct
8525.5° / 9.6°
Nov
5918.9° / 6.4°
Dec
3014.6° / 4.3°
Monthly climate evidence for Napa Soda Springs — daylight is calculated from latitude, everything else is measured
MonthDayNightRainWet daysDaylightComfortCoverage
January14.7°C4.6°C131 mm9.99 h 4631Strong coverage
February17.2°C5.4°C135 mm9.210 h 4241Strong coverage
March19.6°C6.4°C103 mm9.311 h 5055Strong coverage
April22.2°C7.5°C47 mm5.213 h 0877Strong coverage
May24.6°C9.9°C27 mm314 h 1489Strong coverage
June27.8°C12°C6 mm0.914 h 4982Strong coverage
July28.3°C13°C0 mm014 h 3682Strong coverage
August28.6°C13°C1 mm0.113 h 3981Strong coverage
September28.9°C11.9°C2 mm0.512 h 2378Strong coverage
October25.5°C9.6°C33 mm2.911 h 0885Strong coverage
November18.9°C6.4°C76 mm6.110 h 0259Strong coverage
December14.6°C4.3°C137 mm9.49 h 3030Strong coverage

What has changed

Napa Soda Springs runs +1.1°C
on the 1961–1990 baseline.

Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.

Jan
+1.6
Feb
+0.9
Mar
+0.7
Apr
+1.7
May
+0.9
Jun
+1.4
Jul
+0.3
Aug
+0.6
Sep
+1.5
Oct
+1.3
Nov
+0.8
Dec
+0.9
May daytime highs, 20112025. Last recorded: 26.4°C.
Records at NAPA STATE HOSPITAL, 1893–2026
MonthRecord highRecord lowWettest dayWettest / driest monthYears
January29.4°C8 Jan 1962-7.2°C9 Jan 1937145 mm4 Jan 1982382 mm1909 · driest 1 mm in 2015127
February27.2°C28 Feb 1929-5.0°C1 Feb 1917109 mm8 Feb 2014388 mm1986 · driest 0 mm in 2022128
March33.3°C17 Mar 1914-5.0°C8 Mar 194984 mm14 Mar 2003304 mm1995 · driest 1 mm in 1923128
April35.0°C29 Apr 1981-2.8°C22 Apr 192968 mm1 Apr 1996160 mm1896 · driest 0 mm in 1949127
May40.0°C30 May 1910-1.1°C18 May 197447 mm16 May 199695 mm1996 · driest 0 mm in 2017127
June45.0°C14 Jun 19611.1°C17 Jun 192931 mm2 Jun 196766 mm2011 · driest 0 mm in 1901127
July44.4°C14 Jul 19723.3°C13 Jul 192921 mm8 Jul 197427 mm1974 · driest 0 mm in 1952127
August41.7°C15 Aug 20202.8°C17 Aug 193221 mm11 Aug 196533 mm1976 · driest 0 mm in 1931126
September45.6°C6 Sep 20222.2°C22 Sep 193250 mm23 Sep 1904122 mm1904 · driest 0 mm in 1964126
October41.1°C1 Oct 1980-2.2°C29 Oct 1946136 mm24 Oct 2021263 mm1962 · driest 0 mm in 2022127
November32.2°C16 Nov 1895-3.9°C27 Nov 1928149 mm21 Nov 1977267 mm1973 · driest 0 mm in 1936127
December27.2°C26 Dec 1967-10.0°C22 Dec 1990104 mm27 Dec 1931410 mm1955 · driest 0 mm in 1989126
Typical days per month at NAPA STATE HOSPITAL, 1991–2020
MonthDays 25°C+Days 30°C+Frost nightsHeavy rain (10 mm+)
January<1054
February<1025
March4<1<13
April82<12
May1340<1
June2190<1
July25900
August26100<1
September24120<1
October1760<1
November2<1<13
December0054
How often, not how much — every day in NAPA STATE HOSPITAL’s record sorted by what it was actually like, rather than averaged
MonthWarm & dry daysWet daysWashoutsWeek with 3+ wet daysDaytime mean has ranged
January5%32%15%40%12.1–16.3°C
February19%31%14%37%13.8–19.1°C
March36%28%11%31%15.8–21.3°C
April56%17%5%14%18.5–23.7°C
May79%8%2%5%21.5–26.4°C
June95%3%<1%<1%23.8–29.2°C
July99%<1%0%0%25.8–29.7°C
August98%<1%<1%<1%25.9–29.5°C
September96%3%<1%2%25.2–30.7°C
October81%10%4%8%22.8–27.1°C
November37%21%9%26%16.4–21.1°C
December5%30%13%35%12.1–16.6°C

A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.

1893Each stripe is one year’s mean temperature against the 114-year average. Warmest: 2014. Coolest: 1911.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity
GeoNames 5376122
NOAA station
USC00046074 · NAPA STATE HOSPITAL
Station distance
12.6 km from the place centre
Climate period
1991–2020
Minimum month coverage
29 usable years
Daylight
Calculated from latitude 38.39°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Important limit
Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

These places read the same station, so their numbers are identical — distance from NAPA STATE HOSPITAL is what differs

NapaImolaNapa AbajoOak KnollRocktramSalvador