San Diego Weather - Weather Notes and Annual Rainfall
John S. Stokes III - Custom Puzzle Craft
Home

May 22, 2014 - We've had a bunch of record temperatures here - broken or tied. Fire storms accompanied the second batch. I was surprise today, San Diego county remained in "extreme drought" instead of being moved to the worst category "exceptional drought", by the USDA's weekly Drought Monitor update.
----- April 29: 91 degrees, record
----- April 30: 94 degrees, record
----- May 1: 95 degrees, record
----- May 12: 88 degrees, tied record (1967)
----- May 13: 94 degrees, tied record (1967)
----- May 14: 93 degrees, record
----- May 15: 97 degrees, record
----- May 16: 92 degrees, tied record (1956)

January 17, 2014 - For drought commentary along with monthly notes, scroll down to Recent San Diego Rain File Updates.

August 30, 2013 - I created a super cool time-lapse video of the weather for the last four days from mid Monday August 26, 2013 through mid-day Friday, August 30, 2013. In retrospect I should have let the video run through the end of the day on Friday as there were some cool clouds over the mountains later in the day.

 
Please leave comments on YouTube (go HERE to watch this on YouTube)

July 23, 2013 - On July 21 there were some impressive thunderstorms in East County, with Agua Caliente receiving well over an inch of rain. But here along the coast, nothing. The next day was advertised to be a potentially explosive day with a clear morning providing lots of heating for convection over the mountains. I now have better equipment for doing time lapses and I ran the camera facing east for most of the day yesterday. In late morning things were looking up, but drier air began to move in from the coast and things went down hill from there.


Ramping up in the late morning


Fizzling a couple hours later

Today I have the camera running in case something isolated pops up this afternoon, but so far very, very little activity.

San Diego Rain History

As a San Diego resident I've found it hard to find a convenient place to find annual rainfall data for San Diego in a useful format. Most records are kept by calendar year, but San Diego's weather is highly seasonal with most of the rain falling in the November-March time period. I have developed a file of monthly San Diego rainfall data which presents the data by both calendar year AND by season (running from July to June).

The Data File

The file is comma delimited, in the format of:

Year, Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec, YearTotal, NextJan, NextFeb, NextMar, NextApr, NextMay, NextJun, SeasonTotal

DOWNLOAD: File is here (sandiegorain.txt). The data will come up as a separate page. It is easy to bring the data into a spreadsheet. Save the text page. Then open a spreadsheet program and import the data from the saved text file. I try to keep the file "reasonably current". If I'm behind, Contact me and I may update it right away for you - so little time and so many other things to do! Also PLEASE Contact me if you find an error!

Recent San Diego Rain File Updates and Weather Notes

June 30, 2013 11:32 PM - File updated, June zero - and like last year not even a trace! Of course Junes are always dry, with a long term average of just .06". Winter season (July 1 2013 through June 30 2014) came to 5.06", around 50% of normal (NWS says normal is 10.34", my records say 9.86"). Season chart updated. Let's hope for an active monsoon season! After all the heat in April and May, June was a wonderful month temperature-wise!

June 1, 2014 6:39 PM - File updated, just a trace of rain in May, meaning the total was .00".

April 30, 2014 9:35 PM - File updated, April 0.53", .18" below normal. After a dryer than normal winter for the third year in a row, the dry season is now upon us. Today, a strong Santa Ana wind drove the San Diego temperature to 94, breaking the record by an impressive 8 degrees! On top of that, the relative humidity dropped to 4% again, sucking moisture from the pores of life. We are on track to come in at about 50% of normal for the the latest July-June season, barring unusual rain this May and June.

April 1, 2014 4:13 PM - File updated, March 1.28", .53" below normal according the the NWS. With 1.25" of this being recorded in the first two days of March, the remainder of the month resumed drought mode.

March 3, 2014 9:01 AM - Final total for the storm at Lindbergh was 1.90" thanks to some well placed rain banding towards the end, bringing the total close to forecast, with 1.25" of this being recorded in March.

March 1, 2014 4:40 PM - File updated, February came in at exactly 1", which is less than 1/2 of normal.. The big Pacific storm lived up to its billing, particularly with strong winds. However, the rain amounts in the immediate San Diego area have been less than predicted. I think the storm tracked slightly north of the predicted path. The storm total for Lindbergh Field (the airport) is currently about 1.06". One more fairly strong squall is approaching. Palomar Mountain received over 8".

February 27, 2014 1:59 PM - Storm rain predictions raised! Now saying 2.5-5" rain along the coast, 5-10" in the mountains, 1" in the deserts.

February 26, 2014 10:28 PM - Weather service saying this is a once every 5-10 year storm! Low pressure could get to 975 millibars (28.79"), that's really low for around here. But the local rain projection has backed off to 1-2" along the coast and 3-6" in the coastal mount slopes.

February 25, 2014 10:29 PM - Major rains predicted for Southern CA, Friday/Sat (Feb 28-Mar 1), with 2" along the coast and 5-8" in the coastal mountain slopes! Then the jet stream goes back north. Looking forward to the rain.

February 20, 2014 - The San Diego area drought has now been upgraded to "Extreme Drought" condition, and the Los Angeles area to "Exceptional Drought" the most extreme designation. February's total remains at .35". A possibility of rain is predicted for the last day of this month. Should February end up with .35", the last 14 months will be 5.93", the driest in more than 148 years, with 1866 being 5.53".

February 9, 2014 - There have been major rains during the last few days in Northern California with some flooding. But..... here in San Diego, the drought continues. We had .26" a few days ago, bringing February's total to .35", a run rate at around 30% below normal so far. No rain is predicted for the up coming week. The rains up north are a big plus for the state overall.

January 31, 2014 11:02 PM - File updated, January .01", obviously well below normal. There have been no instances of just .01" in January before, and as mentioned only four instances of zero.

The weekly edition of the U.S. Drought Monitor now shows an area of "Exceptional Drought" in mid California, the worst level of the drought scale. San Diego remains in "Severe Drought" state, with most of California in "Extreme Drought" state. The National Weather Service is predicting below normal precipitation for each month February through May, which is basically beyond the end of the rainy season. So this summer is likely going to see major or even drastic water restrictions.

January 29, 2014 - Still no rain this month, but now the Weather Service is saying we could have "LESS THAN ONE TENTH INCH NEAR THE COAST" late tomorrow going into Friday morning, the last day of the month. (Why does the NWS still write their discussions in upper case?). Only four times since 1850 have there been zero Januaries: 1850, 1859, 1948 and 1976. I suspect Jan 1850 could be a result of missing data as that is the very first month in the history file. 1859 was followed by 1.89" in February, 1948 February with just 1.07" and 1976 with a fat 5.40".

From the current long range forecast looks like the first week in February will be dry with perhaps a sprinkle.

January 18, 2014 - I've added a new chart showing the average annual rainfall in San Diego by decade. Scroll down to bottom of page.

January 17, 2014 - Governor Brown declares drought emergency. Today in San Diego the relative humidity reached as low as 4%, this is extraordinarily dry. There has been no rain so far this month and the total since July 1 has been just 2.24". There have been 20 times since 1850 that the total for the Jul-Jan period was less than 2.24" (counting the full month of January), however of these 20 times, only ONE had less rain in the prior Jan-Jun period than we had in 2013 (1863 with just 1.89", 3.33" in 2013). So we are certainly in historic territory. According to the U.S. Drought Monitor we remain in the "Severe Drought" category; however the area of "Extreme Drought" has been spreading south and we could very well be placed in that category soon.

%
San Diego - January 17, 2014 with 6% humidity at the time of the photo

January 1, 2014 - File updated, December .46", well below normal. NOTICE: The text file had an incorrect entry for February 2013. The correct total for February was .63", not .56", this was fixed today. The annual rainfall graph has also been updated. The total for the year was 5.57", well below normal.

December 1, 2013 - File updated, November 1.48", wetter than normal, finally. Almost all fell on November 21 & 22, bit freaky as nearby areas in San Diego didn't receive nearly that much!

November 12, 2013 - File updated, October .25", continuing the drier than normal pattern.

October 4, 2013 - File updated, September .00" (trace). According to the U.S. Drought Monitor, the drought in San Diego is now "Severe". The five levels of drought are: Abnormally Dry, Moderate Drought, Severe Drought, Extreme Drought and Exceptional Drought.

August 31, 2013 - File updated, July .05", August .00" (trace).

July 1, 2013 - File updated, June zero - not even a trace! Winter season comes to 6.43", about 35% below normal. Season chart updated.

The data was derived from NWS records going back to 1850, the link I use to have here no longer works. Some of the totals in the early years may result from incomplete data. Also the rain gage wasn't always at the same exact location, there's a story about this somewhere on the web. I recall it being in something like nine different locations since 1850.

If you are looking for official NWS statistics for recent days and months, go to http://www.weather.gov/climate/index.php?wfo=sgx


Big cumulus over San Diego - Sunday February 8, 2009


San Diego Rainfall by Calendar Year
1850 through 2013
2013 shown in red
year2013

The record calendar year was 1884 with 27.59 inches.


San Diego Rainfall by Season (July 1 through June 30)
1850-1851 through 2013-2014
2013-2014 season shown in red
2013-2014

Is there major climate change going on here in San Diego as indicated by precipitation? According to this chart I prepared from the data file, rainfall has been quite steady when looked at by decade.

SD_rain_by_decade
San Diego average annual rainfall by decade


© John S. Stokes III - Puzzle Crafter & Weather Enthusiast