Drought in San Mateo County, CA: 3.8 years in 10 since 2000

3.8 years in 10

San Mateo County, CA: 10 of 26 full years had 13+ weeks in drought. More drought-prone than most US counties.

20002025

Drought years: 2007 (37 wk), 2008 (26 wk), 2009 (41 wk), 2012 (48 wk), 2013 (35 wk), 2014 (52 wk), 2015 (52 wk), 2020 (44 wk), 2021 (52 wk) and 2022 (52 wk). Not a single drought week in 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2010, 2011, 2017, 2024 and 2025.

Plan for drought as normal: shrink the lawn, go drip and natives

Drought is the normal state of things here. Most of the yard goes to natives and gravel on drip; any grass that stays is a small, tough patch.

If you are replacing turf, plant natives in fall so roots set before the Sep peak, and check your water utility for a turf-removal rebate before you dig.

Against the rest of CA

51st most drought-prone of 58 CA counties; the CA middle is 4.6 in 10. Closest on the list: Napa County (3.8 in 10) and San Francisco County (3.8 in 10). Driest in CA: Imperial County (6.9 in 10). Least drought: Del Norte County (3.1 in 10).

When in the year it hits

Most often in Sep (39% of weeks), then Jun (38%) and Jul (38%). Least in Apr (27%). May to September averages 37%.

33 Jan
28 Feb
29 Mar
27 Apr
33 May
38 Jun
38 Jul
35 Aug
39 Sep
34 Oct
32 Nov
34 Dec

The worst year: 2014

2014: 52 weeks in drought, peaking at D4 exceptional. Across 1,401 weekly maps: 33.3% of all weeks at D1 or worse, 19.7% at D2, 10.1% at D3, 42 weeks with some of the county in D4. Longest unbroken spell: 156 weeks, Mar 3, 2020 to Feb 21, 2023.

Lately

Last drought year: 2022, 52 weeks. 2016-2025: 3 in 10, against 4.4 in 10 for 2000-2015, about the same. So far in 2026: 0 of 44 weeks in drought, through Nov 3, 2026.