San Luis Obispo/San Luis Cnty climate by month
Averages and records for each calendar month at San Luis Obispo/San Luis Cnty, United States, from 1998 to 2026. The warmest month is September, averaging 26.8°C; the coolest is December at 18.7°C.
| Month | Avg high | Avg low | Record high | Record low | Years |
|---|---|---|---|---|---|
| January | 19.0°C | 5.3°C | 32.8°C16 January 2014 | −6.0°C14 January 2007 | 28 / 28 |
| February | 18.8°C | 5.9°C | 31.7°C8 February 2018 | −2.8°C1 February 2002 | 28 / 28 |
| March | 19.7°C | 7.1°C | 36.1°C17 March 2026 | −0.6°C4 March 2002 | 28 / 28 |
| April | 20.5°C | 7.9°C | 38.3°C20 April 2009 | −1.1°C4 April 1999 | 29 / 29 |
| May | 22.1°C | 9.4°C | 39.4°C15 May 2014 | 1.7°C15 May 1999 | 29 / 29 |
| June | 24.1°C | 11.2°C | 39.4°C29 June 2013 | 3.3°C7 June 1999 | 29 / 29 |
| July | 25.9°C | 12.7°C | 38.9°C6 July 2018 | 6.7°C4 July 1999 | 29 / 29 |
| August | 26.5°C | 13.1°C | 43.9°C29 August 2009 | 7.2°C15 August 1999 | 29 / 29 |
| September | 26.8°C | 12.6°C | 47.2°C6 September 2020 | 5.6°C29 September 2019 | 28 / 29 |
| October | 25.4°C | 10.5°C | 42.2°C24 October 2017 | 0.6°C31 October 2019 | 28 / 28 |
| November | 22.0°C | 7.2°C | 35.6°C5 November 2012 | −2.2°C13 November 2000 | 28 / 28 |
| December | 18.7°C | 5.2°C | 31.1°C1 December 2021 | −5.6°C22 December 1998 | 28 / 28 |
Years shows the number behind the average high, then the number holding a record for that month. They differ because a year contributes an average only when the month has at least 25 days of readings, while a single reading is enough to set a record. The average low is withheld on the same 25-day rule and is counted separately again; it is shown as a dash where the archive cannot support it. Across the twelve months here the averages rest on 28 to 29 years each.
See what San Luis Obispo/San Luis Cnty is doing right now
Every figure on this page is computed from NOAA GHCN-Daily observations stored per station, per year, per month. Nothing is modelled, interpolated or estimated, and a month the archive never covered is left out rather than filled in. A station appears here only once all twelve months carry an average from at least 10 years. See how this is built.