Napa weather in May: Napa, California: normal highs, lows, rain and records for May
Napa in May has a normal high of 73°F and a normal low of 48°F, a daily mean of 61°F, rising from 71°F on the 1st to 76°F by the 31st. Measurable precipitation falls on 3 days in a normal May, 0.80 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 23°C and low of 9°C, 20 mm of precipitation in May.
- NOAA stationNapa County Airport
- Station IDUSW00093227
- Location38.21°N 122.28°W
- Elevation14 ft (4 m)
- Population76,921
- Jan 57° 38°
- Feb 61° 40°
- Mar 64° 42°
- Apr 68° 44°
- May 73° 48°
- Jun 78° 52°
- Jul 79° 55°
- Aug 80° 54°
- Sep 80° 51°
- Oct 75° 46°
- Nov 65° 40°
- Dec 57° 38°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Napa in May?
The normal high is 73°F and the normal low 48°F, for a daily mean of 60.5°F. May is 4.7°F warmer than April and 4.6°F cooler than June. May is the 6th warmest month of the year in Napa and the 8th wettest. Across the month the normal high rises 5°F, from 71°F on May 1 to 76°F on May 31. From one year to the next May's mean temperature typically moves about 2.4°F either way (NOAA's standard deviation), so roughly two Mays in three average between 58°F and 63°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 15%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 71°F | 46°F | 15% | 8% |
| May 8 | 72°F | 47°F | 12% | 6% |
| May 15 | 73°F | 48°F | 11% | 6% |
| May 22 | 74°F | 49°F | 9% | 5% |
| May 31 | 76°F | 50°F | 7% | 3% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 71°F | 46°F | 15% | 8% | 13 h 50 min |
| May 2 | 71°F | 46°F | 14% | 7% | 13 h 50 min |
| May 3 | 71°F | 46°F | 14% | 7% | 13 h 50 min |
| May 4 | 71°F | 46°F | 14% | 7% | 13 h 50 min |
| May 5 | 71°F | 46°F | 13% | 7% | 13 h 50 min |
| May 6 | 71°F | 46°F | 13% | 7% | 14 h |
| May 7 | 72°F | 46°F | 13% | 7% | 14 h |
| May 8 | 72°F | 47°F | 12% | 6% | 14 h |
| May 9 | 72°F | 47°F | 12% | 6% | 14 h |
| May 10 | 72°F | 47°F | 12% | 6% | 14 h |
| May 11 | 72°F | 47°F | 12% | 6% | 14 h 10 min |
| May 12 | 72°F | 47°F | 11% | 6% | 14 h 10 min |
| May 13 | 73°F | 47°F | 11% | 6% | 14 h 10 min |
| May 14 | 73°F | 48°F | 11% | 6% | 14 h 10 min |
| May 15 | 73°F | 48°F | 11% | 6% | 14 h 10 min |
| May 16 | 73°F | 48°F | 11% | 6% | 14 h 10 min |
| May 17 | 73°F | 48°F | 10% | 5% | 14 h 20 min |
| May 18 | 73°F | 48°F | 10% | 5% | 14 h 20 min |
| May 19 | 74°F | 48°F | 10% | 5% | 14 h 20 min |
| May 20 | 74°F | 49°F | 10% | 5% | 14 h 20 min |
| May 21 | 74°F | 49°F | 9% | 5% | 14 h 20 min |
| May 22 | 74°F | 49°F | 9% | 5% | 14 h 20 min |
| May 23 | 74°F | 49°F | 9% | 5% | 14 h 30 min |
| May 24 | 75°F | 49°F | 9% | 4% | 14 h 30 min |
| May 25 | 75°F | 49°F | 8% | 4% | 14 h 30 min |
| May 26 | 75°F | 49°F | 8% | 4% | 14 h 30 min |
| May 27 | 75°F | 49°F | 8% | 4% | 14 h 30 min |
| May 28 | 75°F | 50°F | 8% | 4% | 14 h 30 min |
| May 29 | 76°F | 50°F | 7% | 4% | 14 h 30 min |
| May 30 | 76°F | 50°F | 7% | 3% | 14 h 40 min |
| May 31 | 76°F | 50°F | 7% | 3% | 14 h 40 min |
- Normal high
- 73°FMay average
- Normal low
- 48°FMay average
- Precipitation
- 0.80 inmonth total
- Days with precipitation
- 30.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 13 h 50 min to 14 h 40 minMay 1 to May 31
- Days at 70°F or more
- 20
- Days at 80°F or more
- 5
- Sunshine
- 88%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00093227; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Napa in May?
On a given May day the chance of 0.01 inch or more is 11% on average, highest around May 1 (15%). In all, 0.80 in falls on 3 days of a normal May.
In a normal May in Napa, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00093227.
What are the records for May in Napa?
The warmest May temperature on this station's record (since 1998) is 101°F, on May 15, 2008; the coldest is 31°F, on May 23, 2010. The wettest May brought 2.78 in (2019).
The May mean against the 1991-2020 normal of 60.5°F: 2021 61.5°F (+1.0), 2022 61.2°F (+0.7), 2023 59.6°F (−0.9), 2024 60.1°F (−0.4), 2025 61.1°F (+0.6), 2026 61.4°F (+0.9). 4 of 6 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 61.5°F | +1.0°F | 0.03 in |
| 2022 | 61.2°F | +0.7°F | 0.00 in |
| 2023 | 59.6°F | −0.9°F | 0.70 in |
| 2024 | 60.1°F | −0.4°F | 0.69 in |
| 2025 | 61.1°F | +0.6°F | 0.20 in |
| 2026 | 61.4°F | +0.9°F | 0.64 in |
Source: records: ACIS, station USW00093227; recent months: ACIS, station USW00093227. Records and recent months use complete months only.
How does May in Napa compare across California?
Across the 219 places PlainClimate covers in California, May normal highs run from 58°F in Tahoma to 96°F in Needles; Napa's is 73°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.