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🇺🇸 Weather in San Francisco in May
This is what the weather in San Francisco (California, USA) was like in May over the years 2017–2026.
Key facts at a glance
Prevailing weather: Sunny
Avg. daytime high
19.8 °C
17.6 °C – 21.6 °C
Avg. night-time low
10.1 °C
9.6 °C – 11.0 °C
Avg. rain days in period
2.5
8 % of days · ≥ 1.0 mm
Avg. precipitation in period
15.6 mm
0.4 mm – 70.5 mm
Avg. cloud cover
50 %
This data source has no sunshine hours – average cloud cover is shown instead.
Avg. sea temperature
12.6 °C
Sea temperature available for 4 of 10 years.
Extremes: Highest temperature 30.2 °C (24 May 2022) · Lowest temperature 6.1 °C (11 May 2022) · Avg. daily peak wind 20 km/h
Weather mix of all days
- 105Sunny
- 94Partly cloudy
- 86Cloudy
- 19Light rain
- 6Rain
Summary
- On average 19.8 °C during the day and 10.1 °C at night.
- On average 2.5 rain days (Rain day = at least 1.0 mm of precipitation) with 15.6 mm of precipitation in total.
- In 2 of 10 years there was not a single rain day.
- The sea averaged 12.6 °C.
- Prevailing weather: Sunny.
- Warmest year: 2020 (avg. 21.6 °C), coolest: 2023 (avg. 17.6 °C).
- Wettest year: 2019 (70.5 mm), driest: 2021 (0.4 mm).
- Extremes: 30.2 °C on 24 May 2022 and 6.1 °C on 11 May 2022.
Overall values from all 10 years. How is this calculated?
Charts
Temperatures per year
Average over your travel period
Avg. daytime high: 2017 19°, 2018 19°, 2019 18°, 2020 22°, 2021 21°, 2022 21°, 2023 18°, 2024 20°, 2025 21°, 2026 20°. Avg. night-time low: 2017 10°, 2018 10°, 2019 10°, 2020 11°, 2021 10°, 2022 10°, 2023 10°, 2024 10°, 2025 10°, 2026 11°. Sea temperature: 2017 –, 2018 –, 2019 –, 2020 –, 2021 –, 2022 11°, 2023 15°, 2024 –, 2025 12°, 2026 13°.
Precipitation & rain days
Precipitation (mm): 2017 3, 2018 4, 2019 71, 2020 18, 2021 0, 2022 2, 2023 19, 2024 21, 2025 3, 2026 15.
Year by year
2026
Avg. max20.0°Avg. min10.6°- Rain days
- 4 Rain days
- Precipitation
- 14.7 mm
- Avg. cloud cover
- 54 % cloudy
- Sea temperature
- 13.0 °C
Max 26.8 °C · Min 9.3 °C
2025
Avg. max20.7°Avg. min10.3°- Rain days
- 1 Rain days
- Precipitation
- 3.4 mm
- Avg. cloud cover
- 36 % cloudy
- Sea temperature
- 11.8 °C
Max 28.2 °C · Min 8.9 °C
2024
Avg. max20.2°Avg. min9.8°- Rain days
- 1 Rain days
- Precipitation
- 21.2 mm
- Avg. cloud cover
- 35 % cloudy
- Sea temperature
- –
Max 25.7 °C · Min 7.5 °C
2023
Avg. max17.6°Avg. min9.9°- Rain days
- 5 Rain days
- Precipitation
- 19.0 mm
- Avg. cloud cover
- 71 % cloudy
- Sea temperature
- 14.7 °C
Max 25.4 °C · Min 8.3 °C
2022
Avg. max20.9°Avg. min9.6°- Rain days
- 0 Rain days
- Precipitation
- 1.8 mm
- Avg. cloud cover
- 31 % cloudy
- Sea temperature
- 10.9 °C
Max 30.2 °C · Min 6.1 °C
2021
Avg. max21.1°Avg. min10.0°- Rain days
- 0 Rain days
- Precipitation
- 0.4 mm
- Avg. cloud cover
- 37 % cloudy
- Sea temperature
- –
Max 27.2 °C · Min 7.7 °C
2020
Avg. max21.6°Avg. min11.0°- Rain days
- 6 Rain days
- Precipitation
- 17.8 mm
- Avg. cloud cover
- 47 % cloudy
- Sea temperature
- –
Max 29.9 °C · Min 7.6 °C
2019
Avg. max17.7°Avg. min10.0°- Rain days
- 6 Rain days
- Precipitation
- 70.5 mm
- Avg. cloud cover
- 75 % cloudy
- Sea temperature
- –
Max 22.2 °C · Min 7.6 °C
2018
Avg. max19.0°Avg. min10.2°- Rain days
- 1 Rain days
- Precipitation
- 4.5 mm
- Avg. cloud cover
- 62 % cloudy
- Sea temperature
- –
Max 27.8 °C · Min 7.8 °C
2017
Avg. max19.2°Avg. min10.0°- Rain days
- 1 Rain days
- Precipitation
- 2.7 mm
- Avg. cloud cover
- 48 % cloudy
- Sea temperature
- –
Max 26.0 °C · Min 7.3 °C
Frequently asked questions
- How warm is it in San Francisco in May?
- Daytime highs averaged 19.8 °C, night-time lows 10.1 °C. The highest value of the past 10 years was 30.2 °C (24 May 2022), the lowest 6.1 °C (11 May 2022).
- How often does it rain in San Francisco in May?
- On average there were 2.5 rain days (at least 1 mm) with 15.6 mm of precipitation in total. In 2 of 10 years there was no rain day at all.
- How warm is the sea in San Francisco in May?
- The sea temperature averaged 12.6 °C (open-sea point approx. 6 km from the town).
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Other destinations in May
Data sources
- Weather data
- Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. Snow depth is the model value for the grid cell, not the depth on the slopes. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains. - Sea temperature
- MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis) - Sea measuring point approx. 6 km from the location (37.830, -122.450)
- Place search
- Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)