San Diego, CA

Station Overview

Graphical Climatology of Downtown San Diego: Daily Temperatures and Rainfall, by Year (1875 – Present)

The following is a graphical climatology of San Diego, California temperatures and precipitation, from 1875 into 2026. Included are summary overview charts followed by 152 year-to-year graphs depicting daily temperatures, temperature anomalies, and precipitation. The 1875 to 2026 period of record includes observations from eight different but relatively nearby Weather Service Office locations downtown (through 1926) and three at Lindbergh Field (1927-present). The latter is about 1.5 miles to the northwest of Downtown, and about 30 feet lower in elevation (~ 15 feet msl). For the pre-Lindbergh Field era, thermometer placements ranged from 20 ft to 94 ft above ground level, those at Lindbergh Field form 6 to 37 feet above ground level.A small number of missing data, comprising 45 days, or ~.001 % of the record, were filled using observations from nearby Chula Vista. Data were accessed from the Utah Climate Center and NCDC Online sites, plus that of the NWS-San Diego site.

Data Collection 01

Climate Overview Graphs — RECENT YEARS

Data Collection 02

San Diego Misc. Rainfall & Temperature Graphs

Data Collection 03

Climograms For San Diego And Other Charts:

Mean & Extreme Temps (99% & 1% Percentile Levels)
Mean & Extreme Rel Hum’s (1% Percentile Levels)
Winds (Mean Vector, Prevailing, & Mean Scalar)
Mean & Extreme (Sustained) Winds (99% Percentile Level)
Cloud Ceilings
Fog/Haze
Blowing Sand/Dust
Thunderstorms
K-Means Cluster Analysis of San Diego Lindbergh Field Resultant Wind Patterns
Record Warmest Max/Min Temperature Days, by Calendar Day (1875-2021)Record Coldest Max/Min Temperature Days, by Calendar Day (1875-2021)
Record Coldest Max/Min Temperature Days, by Calendar Day (1875-2021)Record Warmest Max/Min Temperature Days, by Calendar Day (1875-2021) Record Coldest Max/Min Temperature Days, by Calendar Day (1875-2021)

Data Collection 04

Year-To-Year Graphs – Interpretation

The uppermost chart for a given year’s page (accessed by the links below) are “floating-bars” of the year’s daily maxima and minima temperatures. Superimposed on the bars are two line traces, the upper one connecting 1875 to present mean daily maxima, the lower one mean daily minima. The bars depict the varying diurnal, synoptic, long-wave, seasonal, and sea-surface temperature anomaly influences on San Diego temperature over time.

The second chart down shows the day-to-day mean temperature anomalies (daily mean temperature less the corresponding long-term climatological mean). Vertical lines extending upward from the zero line indicate above average means for the day (colored red), those extending downward indicate below average daily means (colored blue). In general, the most extreme departures for San Diego are positive, reflecting to a large extent the occurrence of warming offshore flow episodes.

(Note: Clicking the floating-bar charts a second time after they appear on the screen will enlarge them even further).

Data Collection 05

Year-To-Year Graphs — OLDER YEARS

The third chart down shows the second chart’s anomalies in deseasonalized (“standardized”) form. Standarized stats or "z-scores" of plus or minus 3.0 occur just 0.8% of the time; nearly all of these (95%) positively signed, reflecting extreme warming offshore flow events and in some cases, positive sea-surface temperature anomalies. Greatest positive standardized departure in the record is the amazing +6.6z for 25 May 1896 , greatest negative –4.2z for 6 January 1913 .

The bottom chart depicts daily precipitation totals, as high as 3.23 inches (5 April 1926).

Data Collection 06

Links To Some Of The More Interesting Year-To-Year Graphs, With Accompanying Notes

In midst of usual “June-gloom” period, three successive 90 F days early in the month.

100 F on 11 September..

In an otherwise cool year, abbreviated hot spells scattered throughout the year, especially 99 F on 29 March, warmest in history for March down to the present.

Second coolest year in San Diego history down to the present. Coolest March, July, August, and Fall (September-November).

Abrupt warming in late-May.

Coldest November in history.

Early June heat. Long Warm Spells in November and December.

In an otherwise cool year, very warm over August and early September.

Coolest year in San Diego history. Coolest January and calendar month (49.1 F) until January 1949. Also coolest Spring (March-May).

98 F/70 F on 25 May, 6.5 standard deviations above average for the day. Highest temperature ever recorded in May down to present.

Coolest Summer in history (63.9 F).

New

Wettest July in history (0.92″) until 2015 . New (7/20/15)

Coolest May and June in history.

25 F on 7 January coldest temperature ever recorded in San Diego; 110 F on 17 September the warmest until 1963.

Coolest Fall (September-November) in history.

Wettest May (2.54″) and wettest December (9.26″) in history.

Strong El Nino year. Wettest April in history (5.37″). Warmest year in the record up to this time.

100 F on 30 July wamest temperature ever recorded in that calendar month.

Warmest year to date.

Coolest September in history.

Wettest September in history (2.58″), 106 F on 21 September.

January coldest calendar month in history (47.8 F).

88 F on 10 January warmest in all history for this calendar month.

98 F on 30 August wamest temperature ever recorded in this calendar month; 104 F the next day, 1 September.

Warmest year to date.

Warmest year to date record broken after one year.

107 F on 14 October, warmest October reading in all history.

111 F on 26 September highest temperature ever recorded in San Diego history.

Strong ’65-’66 El Nino brings early heavy rains. Wettest November in history (5.82″) and fourth wettest December (6.60″).

97 F on 1 November sets high mark for that month.

Warmest year to date. Six of next nine years including ’76 all warmer than any previous ones in history. 97 F on 4 November ties high mark for that month. Warmest November in history.

Wettest August in history (2.13″), warmest December (63.2 F).

Warmest March in history; 5th wettest (5.00″).

Remarkable four-day hot spell over June 10-13 with daily means each 5 standard deviations or more above average; 101 F on 10th, highest temperature ever recorded in June.

Warmest February in history (63.5 F)

Warmest year in history to date. Warmest June and warmest Summer (June-August – 74.8 F).

Second warmest year in history to date. Warmest August (77.4 F), October (72.2 F), and Fall (September-November).

Warmest year in history until 2014. Also warmest Spring (March-May), warmest July (77.2 F), and warmest calendar month (78.9 F for September).

Coolest year since 1975.

Wettest June in history (0.87″)

Wettest March (6.96″) since 1867’s 7.88″.

Warmest April in history.

Wettest January in history (9.09″)

90 F on 19 February warmest ever for this particular calendar month.

Warmest May in history.

Wettest February (7.65″) since 1884.

Coolest year since 1964.

Warmest January in history.

98 F on 20 April highest ever for this calendar month.

New

100 F on 4 November sets new record maximum for the month

Warmest Year in History

Wettest July in History (1.70″)

* Member, American Meteorological Society

Data Collection 07

Analytics

Sample Regimes, PCA Modes, PDFs & Extremes+

Temperature+

Regimes+

Sample analysis: group years by recurring coastal temperature patterns for San Diego, then compare transitions between common, unusual and persistent regimes. This is sample Analytics content for layout and workflow testing. Replace it with the station’s verified analysis when the final material is ready.

PDFs+

Sample analysis: compare the central distribution and tail behavior of daily temperature observations at San Diego. This is sample Analytics content for layout and workflow testing. Replace it with the station’s verified analysis when the final material is ready.

Rainfall+

Regimes+

Sample analysis: group years by recurring rainfall patterns for San Diego, then compare transitions between common, unusual and persistent regimes. This is sample Analytics content for layout and workflow testing. Replace it with the station’s verified analysis when the final material is ready.

Extremes+

Sample analysis: review the upper and lower tails of the rainfall record for San Diego and identify years that merit detailed chart interpretation. This is sample Analytics content for layout and workflow testing. Replace it with the station’s verified analysis when the final material is ready.