5-day weather forecast San Francisco 18-05-2026

Weather forecast San Francisco Monday, May 18 18.05.2026: sunny, temperature from 13 °C to 19 °C.

No precipitation expected. Wind up to 9.69 m/s (gusts 18.08 m/s). Air humidity 32–78%, atmospheric pressure 758–761 mm Hg, UV index up to 8.5.

Sunrise 05:58
Sunset 20:15

Waxing Crescent2% illuminated
Moonrise 07:15 · Moonset 23:10

Chart

Table

← Sun, May 17

Mon, May 18, 2026

Tue, May 19 →

Forecast from 13 °C to 19 °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)	17	17	18	18	17	17	17	17	17	18	19	19	19	19	18	19	19	18	17	16	15	14	14	13
Precipitation (mm/hr)	0	0	0	0	0	0	0	0	0	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 (%)	0	0	0	0	0	1	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Rain chance (%)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

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)	4.89	5.31	7.39	8.81	9.69	9.69	8.69	7.5	6.11	6.19	5.81	4.81	4	4.39	4.81	5.39	6.31	7.11	6.31	5.31	3.81	2.61	2.11	1.61
Wind gust (m/s)	10.28	11.14	15.39	16.97	18.08	17.72	15.89	13.42	10.78	10.81	10.22	8.58	7.14	7.64	8.06	8.97	11.03	12.44	11.22	9.44	6.94	4.72	3.83	2.97
Wind direction (°)	N 0°	N 350°	N 350°	N 354°	N 0°	N 1°	N 358°	N 358°	N 2°	N 2°	N 359°	N 357°	NNW 329°	WNW 302°	W 281°	W 277°	WNW 286°	WNW 288°	WNW 287°	WNW 285°	W 275°	W 267°	W 259°	WSW 249°

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 (%)	39	38	33	32	32	33	35	37	38	36	35	34	35	38	44	45	44	47	51	61	71	75	77	78

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)	758	758	758	758	758	758	759	759	760	760	760	760	760	760	760	760	760	759	759	759	760	760	761	761

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	0.2	0.9	2.2	4	6.1	7.8	8.5	8.2	6.8	4.8	2.8	1.3	0.4	0	0	0	0

Air quality & pollen

Air quality
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
PM2.5 (µg/m³)	3.9	4.2	4.5	5.3	7.3	8.9	9	9.3	9.9	10.1	10.2	10.4	10.5	10.4	10.5	10.8	10.9	11.3	11.7	12.2	12.1	12.2	12.4	12.7
PM10 (µg/m³)	4.7	5.2	5.5	6.8	9.8	12.6	12.7	13.5	14.5	14.7	14.8	15	15.1	14.9	14.9	15.2	15.2	15.7	16.2	16.7	16.2	16	16	16
Ozone (O₃) (µg/m³)	68	68	70	74	77	80	82	84	85	86	84	79	73	66	60	55	50	47	45	43	42	41	40	38
NO₂ (µg/m³)	7.3	7.6	8.1	8.7	8.7	7.8	6.3	5.2	4.6	4.4	4.9	6.4	8.6	10.7	12.7	14.7	16.1	16.8	16.9	16.8	16.4	15.9	15.6	16
SO₂ (µg/m³)	1.6	1.6	1.6	1.6	1.6	1.6	1.5	1.5	1.5	1.4	1.4	1.4	1.4	1.4	1.4	1.5	1.5	1.5	1.5	1.5	1.5	1.5	1.5	1.6
CO (µg/m³)	139.9	141.9	140.9	138.9	136.9	136.9	136.9	136.9	135.9	135.9	135.9	137.9	141.9	143.9	144.9	144.9	144.9	143.9	141.9	139.9	137.9	136.9	138.9	145.9

← Sun, May 17

Mon, May 18, 2026

Tue, May 19 →

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 →