154
FXUS66 KSGX 050936
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
236 AM PDT Mon Oct 5 2026

.SYNOPSIS...
Widespread Major to locally Extreme HeatRisk will continue for the
coastal areas into the western valleys through Thursday with high
temperatures for the valleys of 100 to 105 each day. A low pressure
system developing over the western states for Monday of next week
will bring a cooling trend for Friday through next weekend with
high temperatures cooling to 4 to 8 degrees below average for next
Sunday.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

.SHORT TERM (Today through Wednesday)...
A weak sea breeze will cool high temperatures near the coast a few
more degrees today with not much change farther inland with the
hottest high temperatures for today, of 100 to 105, for the
western valleys and inland Orange County. Onshore flow on Tuesday
will cool high temperatures a few more degrees along the coast
with slight cooling extending inland into the valleys. On
Wednesday, high temperatures will cool a few more degrees near the
coast with the mountains, deserts, and inland valleys warming a
few to around 5 degrees.

On Wednesday, high temperatures will still be mostly 15 to 20
degrees above average for the valleys and inland coastal areas
with the coast 10 to 15 degrees above average. High temperatures
on Wednesday will be in the mid 80s to lower 90s near the coast to
the upper 90s to 105 for the Inland Empire.

&&

.LONG TERM (Thursday through Sunday)...
On Thursday, there will only be slight changes in high
temperatures for most areas with inland Orange County and the
Inland Empire cooling a few to around 5 degrees. A low pressure
system developing over the western states for Monday of next week
will bring a cooling trend for Friday through next weekend with
high temperatures cooling a few to around 5 degrees on Friday and
another 4 to 8 degrees on Saturday and again on Sunday. High
temperatures on Sunday will be around 4 to 8 degrees below
average, ranging from the 70s near the coast to the lower to mid
80s for the Inland Empire with the lower deserts in the lower to
mid 90s.

&&

.AVIATION...
050530Z...Coast/western valleys: SKC and VFR through Monday.
Moderate to high confidence for typical onshore W/NW winds through
late Monday morning and afternoon.


Inland Valleys/Foothills/Mountains: Easterly breezes increase after
10Z over west facing foothills and eastern valleys, gusting to 15-25
kts, turning westerly once again over the eastern valleys Monday
afternoon. MOD UDDFS expected over coastal slopes. Otherwise...Clear
skies through the TAF period.

&&

.MARINE...
No hazardous marine conditions are expected through Thursday.

&&

.BEACHES...
A 4-5 foot south swell with a period of 12-13 seconds arrives
Tuesday afternoon. Elevated surf of 3-6 feet on south and southwest-
beaches expected. High tides are expected to peak between 6.5 and
7.0 feet during the morning and evenings. In combination with the
elevated surf, minor coastal flooding and beach erosion will be
possible during high tides through the end of the week.

.CLIMATE...
San Diego International Airport had a high temperature of 105 on
Saturday and 100 on Sunday, both new daily record high
temperatures. Prior to this past weekend, the last time San Diego
had a high temperature of 100 or higher was in 2020 on September
6th at 100. The last time San Diego had a high temperature of 100
or higher more than once in a year was in 1979 with high
temperatures of 101 on June 10th and 100 on September 15th. The
last time San Diego had a high temperature of 100 or higher on
consecutive days was in 1965 on October 21st and 22nd at 101 and
104.

Consecutive days with high temperatures of 100 or higher at San
Diego has now only happened four times with temperatures records
dating back to 1874. That also happened in 1963 in September on
the 26th and 27th with 111 and 104 with 111 the all-time record
high temperature for San Diego. It also happened in 1939 on three
consecutive days on September 20th through 22nd with high
temperatures of 100, 106, and 102. That was during the heatwave
that preceded the tropical storm that made landfall near San Pedro
on September 25th, 1939.

San Diego has now had high temperatures of 100 or higher on only 31
days since 1874, 27 of which were in September (20) or October (7).

There have been only three times that San Diego has had a low
temperature of 74 or higher with a high temperature of 100 or
higher. There were low temperatures in 1939 of 74 on September
20th and 76 on September 21st. The low temperature on Sunday,
October 4th of this year was 74, tied for the second warmest low
temperature on a day with a high temperature of 100 or higher.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Extreme Heat Warning until 8 PM PDT Thursday for Orange County
     Coastal Areas-Orange County Inland Areas-San Bernardino and
     Riverside County Valleys-The Inland Empire-San Diego County
     Coastal Areas-San Diego County Valleys-Santa Ana Mountains
     and Foothills.

     Beach Hazards Statement from Tuesday afternoon through Friday
     evening for Orange County Coastal Areas-San Diego County
     Coastal Areas.

PZ...None.

&&

$$

PUBLIC/CLIMATE...17
AVIATION/MARINE/BEACHES...MM

NWS San Diego (SGX) Office