5-day weather forecast San Francisco Sep 20, 2026

16°14° · Overcast

Weather forecast San Francisco Sunday Sep 20, 2026: overcast, temperature from 14 °C to 16 °C.

Precipitation probability 29%. Wind up to 6.81 m/s (gusts 8.83 m/s). Air humidity 81–89%, atmospheric pressure 759–761 mm Hg, UV index up to 5.

Weather Alerts

MinorSep 15, 08:42 PM — Sep 16, 04:45 AMTranslate with Google

Small Craft Advisory issued September 15 at 8:42PM PDT until September 16 at 9:00PM PDT by NWS San Francisco CA

Small Craft Advisory

* WHAT...West winds 10 to 15 kt with gusts up to 25 kt and choppy waters expected. * WHERE...San Francisco Bay South of the Bay Bridge. * WHEN...From 9 AM to 9 PM PDT Wednesday. * IMPACTS...Conditions will be hazardous to small craft.

Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions.

MinorSep 15, 02:17 PM — Sep 15, 10:30 PMTranslate with Google

Small Craft Advisory issued September 15 at 2:17PM PDT until September 16 at 9:00PM PDT by NWS San Francisco CA

Small Craft Advisory

* WHAT...West winds 10 to 15 kt with gusts to 25 kt and choppy waters expected. * WHERE...San Francisco Bay South of the Bay Bridge. * WHEN...From 9 AM to 9 PM PDT Wednesday. * IMPACTS...Conditions will be hazardous to small craft.

Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions.

5 days at a glance — tap a day to open it

Sunrise 06:55
Sunset 19:10

Waxing Gibbous73% illuminated
Moonrise 16:24 · Moonset 01:05

Chart

Table

← Sat, Sep 19

Sun, Sep 20, 2026

Forecast from 14 °C to 16 °C and precipitation

Temperature & Precipitation
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Temperature (°C)	15	15	15	15	15	15	15	15	15	15	15	16	16	16	16	16	16	16	15	15	15	15	14	14
Precipitation (mm/hr)	0	0	0	0.01	0.01	0.02	0	0	0.01	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Cloud cover and precipitation probability

Cloud cover & Rain chance
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Cloud cover (%)	96	73	100	65	74	100	100	100	100	100	99	98	99	100	100	85	70	55	61	66	72	73	74	74
Rain chance (%)	27	22	28	20	23	29	27	27	28	26	25	24	24	24	25	22	19	16	18	20	23	22	23	23

Wind speed and direction

Wind & Wind gust
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Wind (m/s)	5.81	5.69	5.61	6.19	6.81	5.31	5.11	4.89	4.69	4.5	4.19	4	4.39	4.89	5.31	5.39	5.39	5.5	5.39	5.31	5.19	5	4.89	4.69
Wind gust (m/s)	7.64	7.33	7.22	8.11	8.83	6.72	6.5	6.19	5.92	5.39	4.81	4.31	4.69	5.11	5.5	5.81	6	6.31	6.19	6.11	6.03	5.81	5.5	5.25
Wind direction (°)	W 268°	W 270°	W 271°	W 277°	W 281°	W 275°	W 274°	W 274°	W 273°	W 263°	WSW 253°	WSW 243°	WSW 245°	WSW 247°	WSW 249°	WSW 252°	WSW 256°	W 260°	W 260°	W 259°	W 259°	WSW 255°	WSW 251°	WSW 246°

Air humidity

Humidity
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Humidity (%)	88	87	86	87	87	86	86	86	86	84	83	81	81	81	81	82	82	83	85	87	89	88	88	88

Atmospheric pressure

Pressure
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Pressure (mm Hg)	761	761	761	761	761	761	761	761	761	761	761	761	761	761	760	760	760	759	759	759	760	759	759	759

Ultraviolet index

UV Index
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
UV Index	0	0	0	0	0	0	0	3	3	4	4	4	4	4	4	5	4	5	4	4	0	0	0	0

Air quality & pollen

Air quality is available for the first three days only.

← Sat, Sep 19

Sun, Sep 20, 2026

San Francisco on the map

Data Sources & Methodology

Our weather forecasts are powered by a professional weather data provider that aggregates data from national weather services, satellite observations, radar networks, and over 80,000 weather stations worldwide. Forecast data is updated multiple times daily. We convert raw data into clear summaries — wind speed in m/s, pressure in mmHg — so you can plan your day with confidence.

Learn more about our methodology →