KSFO — SAN FRANCISCO
San Francisco, CA, US · America/Los_Angeles · 37.6190°, -122.3749° · 3m elevation
Daily METAR Observations
| Time | Temperature | Dew Point | Humidity | Wind | Wind Speed | Wind Gust | Pressure | Precip. | Condition |
|---|---|---|---|---|---|---|---|---|---|
| 12:56 AM | 56 °F 55.9 °F 13 °C 13.3 °C | 52 °F 52 °F 11 °C 11.1 °C | 87 % | W | 20 mph 17 kt 32 km/h | 0 mph 0 kt 0 km/h | 30.05 in | 0.0 in | Partly Cloudy |
| METAR KSFO 130756Z 26017KT 10SM FEW008 SCT011 13/11 A3005 RMK AO2 PK WND 26027/0710 SLP176 T01330111 401670106 | |||||||||
| 1:30 AM | 56 °F 55.9 °F 13 °C 13.3 °C | 52 °F 52 °F 11 °C 11.1 °C | 87 % | W | 17 mph 15 kt 28 km/h | 0 mph 0 kt 0 km/h | 30.05 in | 0.0 in | Mostly Cloudy |
| SPECI KSFO 130830Z 27015KT 10SM FEW008 BKN011 13/11 A3005 RMK AO2 T01330111 | |||||||||
| 1:48 AM | 56 °F 55.9 °F 13 °C 13.3 °C | 52 °F 52 °F 11 °C 11.1 °C | 87 % | W | 15 mph 13 kt 24 km/h | 0 mph 0 kt 0 km/h | 30.05 in | 0.0 in | Partly Cloudy |
| SPECI KSFO 130848Z 27013KT 10SM FEW007 SCT011 13/11 A3005 RMK AO2 T01330111 | |||||||||
| 1:56 AM | 56 °F 55.9 °F 13 °C 13.3 °C | 52 °F 52 °F 11 °C 11.1 °C | 87 % | W | 16 mph 14 kt 26 km/h | 0 mph 0 kt 0 km/h | 30.05 in | 0.0 in | Partly Cloudy |
| METAR KSFO 130856Z 27014KT 10SM FEW007 SCT011 13/11 A3005 RMK AO2 SLP176 T01330111 50009 | |||||||||
| 2:34 AM | 56 °F 55.9 °F 13 °C 13.3 °C | 52 °F 52 °F 11 °C 11.1 °C | 87 % | W | 14 mph 12 kt 22 km/h | 0 mph 0 kt 0 km/h | 30.05 in | 0.0 in | Mostly Cloudy |
| SPECI KSFO 130934Z 28012KT 10SM FEW007 BKN012 13/11 A3005 RMK AO2 T01330111 | |||||||||
| 2:56 AM | 56 °F 55.9 °F 13 °C 13.3 °C | 53 °F 53.1 °F 12 °C 11.7 °C | 90 % | W | 23 mph 20 kt 37 km/h | 32 mph 28 kt 52 km/h | 30.06 in | 0.0 in | Mostly Cloudy |
| METAR KSFO 130956Z 27020G28KT 10SM FEW005 BKN009 BKN014 13/12 A3006 RMK AO2 PK WND 27028/0956 SLP179 T01330117 | |||||||||
| 3:56 AM | 56 °F 55.9 °F 13 °C 13.3 °C | 53 °F 53.1 °F 12 °C 11.7 °C | 90 % | W | 20 mph 17 kt 32 km/h | 0 mph 0 kt 0 km/h | 30.07 in | 0.0 in | Mostly Cloudy |
| METAR KSFO 131056Z 27017KT 10SM FEW005 BKN008 BKN011 13/12 A3007 RMK AO2 PK WND 27028/1027 SLP181 T01330117 | |||||||||
Time Series
Summary
| Temperature (°F) Temperature (°C) | Actual | |
| High Temp | ||
| Low Temp | ||
| Day Average Temp | ||
| Precipitation (in) | Actual | |
| Precipitation | ||
| Dew Point (°F) Dew Point (°C) | Actual | |
| High | ||
| Low | ||
| Average | ||
| Humidity (%) | Actual | |
| Average Humidity | ||
| Wind (mph) Wind (kt) Wind (km/h) | Actual | |
| Max Wind Speed | ||
| Max Wind Gust | ||
| Visibility | ||
| Pressure (in) | Actual | |
| Average Pressure | ||
| Astronomy | Day Length | Rise / Set |
| Actual Time | 14h 11m | 5:59 AM / 8:11 PM |
| Civil Twilight | 5:32 AM / 8:39 PM | |
| Nautical Twilight | 4:56 AM / 9:15 PM | |
| Astronomical Twilight | 4:17 AM / 9:54 PM | |
| Moon: Waning Crescent | ||
Methodology
Day Boundaries & Time
A "day" is defined as midnight to midnight (00:00:00 through 23:59:59) in the station's local time, using the IANA timezone assigned to each station (e.g. America/Chicago, Europe/London). Daylight Saving Time transitions are respected automatically — when a station's local clocks spring forward or fall back, the UTC boundaries of the day shift accordingly. This means a "day" in the spring DST transition is 23 hours, and in the fall transition it is 25 hours. All observations are stored internally in UTC and converted to local time for display.
Temperature
The FAA reports temperature in degrees Celsius. Values are stored to one decimal place — if a source value has additional precision, it is rounded on storage. Fahrenheit values are computed as °F = °C × 9/5 + 32. All temperatures are displayed as whole numbers (rounded to the nearest integer) in both Celsius and Fahrenheit. High and low temperatures are the maximum and minimum observed values for the day. The day average is the arithmetic mean of all observed temperatures, rounded to the nearest whole number.
Dew Point & Relative Humidity
Dew point is stored and displayed using the same rounding method as temperature (whole numbers). Relative humidity is not reported directly in METARs — it is calculated from the temperature and dew point using the Magnus formula: RH = 100 × exp[(17.27 × Td)/(237.7 + Td) − (17.27 × T)/(237.7 + T)], where T is temperature and Td is dew point, both in °C. The result is rounded to the nearest whole percent and clamped between 0% and 100%.
Wind
Wind direction is reported in degrees true (0–360). The compass direction shown (N, NNE, NE, etc.) divides the compass into 16 sectors of 22.5° each. Variable winds (reported as "VRB" in the METAR) are displayed as "CALM". Wind speed is reported in knots (integer). Miles per hour is computed as mph = kt × 1.15078 and kilometers per hour as km/h = kt × 1.852, both displayed as whole numbers. Wind gust is shown only when the METAR includes a gust value.
Pressure
The altimeter setting is reported in inches of mercury (inHg) to two decimal places. This is the station pressure corrected to sea level and is the value displayed. When the METAR also includes sea level pressure in millibars, that value is used in daily summary calculations.
Precipitation
Precipitation accumulations (1-hour, 3-hour, 6-hour, and 24-hour) are included when reported by the station. A value of 0.0005 inches represents trace precipitation in the FAA convention. The daily total in the summary is the sum of all 1-hour accumulations that exceed trace. Not all stations report precipitation data.
Sky Condition & Weather
The "Condition" column is derived from two METAR fields. If a weather phenomena code is present (e.g. RA for rain, SN for snow, FG for fog, TSRA for thunderstorms), it takes priority and the intensity prefix (- for light, + for heavy) is included. When no active weather is reported, the condition is derived from the highest sky cover layer: CLR/SKC/FEW = Fair, SCT = Partly Cloudy, BKN = Mostly Cloudy, OVC = Overcast.