Monthly climate guide
Napa weather in May
Expect warm weather in Napa in May: afternoons reach about 23°C (74°F), while nights drop to around 9°C (48°F). Around 18 mm of rain falls over the month (very dry), and skies are a mix of sun and cloud. Daytime highs are 4°C warmer than April and 6°C cooler than June.
What stands out in May
- Temperatures are climbing — June is around 6°C warmer.
- In Napa, May is late spring.
- Afternoons and nights feel like different seasons, roughly 14°C apart.
- It's one of the drier months, with about 66% less rain than Napa's average.
Avg high
23°C
74°F
Avg low
9°C
48°F
Rainfall
18 mm
very dry
Humidity
68%
relative
Sky
37%
cloud · a mix of sun and cloud
Napa weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 14°C / 56°F | 4°C / 39°F | 116 mm | 83% | 55% |
| February | 15°C / 58°F | 4°C / 40°F | 114 mm | 79% | 47% |
| March | 16°C / 61°F | 6°C / 42°F | 119 mm | 81% | 55% |
| April | 19°C / 67°F | 7°C / 45°F | 39 mm | 75% | 44% |
| May | 23°C / 74°F | 9°C / 48°F | 18 mm | 68% | 37% |
| June | 29°C / 85°F | 12°C / 54°F | 8 mm | 54% | 22% |
| July | 32°C / 89°F | 14°C / 56°F | 0 mm | 48% | 19% |
| August | 32°C / 90°F | 14°C / 57°F | 0 mm | 49% | 24% |
| September | 31°C / 87°F | 14°C / 57°F | 4 mm | 48% | 22% |
| October | 26°C / 79°F | 11°C / 52°F | 27 mm | 52% | 29% |
| November | 18°C / 65°F | 7°C / 44°F | 71 mm | 68% | 43% |
| December | 13°C / 56°F | 4°C / 39°F | 114 mm | 78% | 49% |
What to pack for May
- T-shirts plus a light layer for the evening
- Comfortable trainers or sandals for long walks
- An extra layer — evenings are noticeably cooler than afternoons
- Sunglasses
Is May a good time to visit Napa?
Compare the months in the chart above to find your ideal window.
Best time to visit Napa →Other United States cities in May
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Napa weather in May. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/usa/napa/may
<a href="https://weathercompare.eu/weather/usa/napa/may">Napa weather in May</a> (WeatherCompare)
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Napa in May: quick answers
Is May a good time to visit Napa?
Yes. May is one of the best months for Napa, with highs around 23°C and about 18 mm of rain.
How warm is Napa in May?
Average highs are about 23°C (74°F) and average lows about 9°C (48°F), based on 10 years of daily data.
Does it rain a lot in Napa in May?
Napa typically gets around 18 mm of rain in May — very dry.
Figures are long-term averages for the area around Napa (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.