Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Granite Hills enjoys a temperate climate with an average annual temperature of 65°F (18°C). Winters average 56°F in January while summers reach 75°F in July / relatively mild seasonal variation. The area gets 330 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 11.6 inches (drier than the 38-inch national average). Air quality is rated Good with a median AQI of 48. The city sits at an elevation of 650 feet.
Temperature
56°F Jan (13°C)75°F Jul (24°C)
Annual Average
65.2°F
21% above US avg
January Average
56°F (13°C)
July Average
75°F (24°C)
Sunny Days
330 days/yr
Geography
Elevation
650 ft (198 m)
Area
2.8 sq mi (7.2 km²)
Population Density
1,386/sq mi
Coordinates
32.8033°N, 116.9056°W
Timezone
America/Los_Angeles
County
San Diego County County
Nearest Airport
San Diego International (SAN) 17 miles away
Precipitation & Snow
Annual Rainfall11.6"
69% below US avg
Snowfall0.0"
Wettest Month (Jan)2.56"
Driest Month (Jun)0.08"
Air Quality
AQI Median
48.0
Rating
Good
Natural Hazard Risk
Overall Risk
Very High
Risk Score
99.7 / 100
Social Vulnerability
24.8 / 100
Community Resilience
8.3 / 100
Hazard Breakdown
Tornado
Relatively Low
Hurricane
Very Low
Earthquake
Relatively High
Wildfire
Very High
Flood
Very High
Hail
Relatively Moderate
Strong Wind
Relatively Moderate
Heat Wave
Relatively High
Winter Weather
Relatively Low
Lightning
Relatively Moderate
Drought
Relatively Low
Cold Wave
Very Low
Landslide
Relatively High
Coastal Flood
Relatively Moderate
Tsunami
Relatively Low
Volcano
Very Low
Avalanche
Very Low
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
9,731 earthquakes (M2.5+) recorded within 150 km since 1990.
Strongest on record: M6.1.
Apr 23, 1992
The 1992 Joshua Tree, California Earthquake
M6.1
140 km
12 km
Jun 15, 2010
8km ESE of Ocotillo, CA
M5.7
94 km
9 km
Jul 7, 2010
20km NNW of Borrego Springs, CA
M5.4
79 km
12 km
Aug 26, 2012
4km NNW of Brawley, CA
M5.4
130 km
8 km
Aug 26, 2012
5km NNW of Brawley, CA
M5.3
128 km
8 km
Mar 23, 1994
35km E of Maneadero, B.C., MX
M5.3
136 km
5 km
Apr 4, 2010
15km SSW of Progreso, B.C., MX
M5.3
126 km
10 km
Sep 15, 1992
9km SE of Yucca Valley, California
M5.3
149 km
7 km
Jun 5, 2021
11km W of Calipatria, CA
M5.3
124 km
6 km
Apr 14, 2025
5 km S of Julian, CA
M5.2
39 km
14 km
Jun 12, 2005
10km ESE of Anza, CA
M5.2
87 km
13 km
Jun 10, 2016
20km NNW of Borrego Springs, CA
M5.2
82 km
12 km
Oct 31, 2001
16km ESE of Anza, CA
M5.0
86 km
14 km
Aug 21, 1993
12km S of Joshua Tree, California
M5.0
147 km
8 km
Jun 28, 1992
7km SSW of Yucca Valley, California
M5.0
146 km
5 km
Jun 30, 1992
14km ENE of Desert Hot Springs, CA
M5.0
142 km
1 km
Jun 15, 2004
67km SE of San Clemente Is. (SE tip), CA
M5.0
108 km
10 km
May 4, 1992
16km NNE of Thousand Palms, California
M5.0
138 km
12 km
May 18, 1992
15km E of Desert Hot Springs, California
M5.0
138 km
6 km
Jul 24, 1992
13km NE of Thousand Palms, California
M5.0
135 km
7 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
30 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF1. Total: 4 injuries.
Date
Rating
Distance
Path
Fatalities
Feb 19, 2005
EF1
79 km
2.8 mi
0
Nov 10, 2000
EF1
20 km
0.4 mi
0
Jan 29, 1998
EF1
46 km
0.5 mi
0
Mar 27, 1991
EF1
46 km
0.2 mi
0
Mar 19, 1991
EF1
19 km
1.0 mi
0
Feb 20, 1980
EF1
28 km
0.1 mi
0
Dec 18, 1978
EF1
63 km
0.8 mi
0
Oct 8, 1961
EF1
58 km
0.1 mi
0
Apr 13, 1956
EF1
25 km
0.1 mi
0
Aug 16, 2018
EF0
87 km
0.2 mi
0
Sep 22, 2007
EF0
43 km
0.1 mi
0
Mar 11, 2006
EF0
33 km
2.0 mi
0
Mar 10, 2006
EF0
46 km
0.2 mi
0
Feb 23, 2005
EF0
25 km
0.1 mi
0
Feb 19, 2005
EF0
72 km
2.2 mi
0
Feb 19, 2005
EF0
70 km
2.5 mi
0
Oct 17, 2004
EF0
63 km
0.2 mi
0
Jul 12, 1999
EF0
50 km
0.1 mi
0
Feb 8, 1998
EF0
43 km
3.0 mi
0
May 20, 1997
EF0
77 km
0.1 mi
0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Tsunami History
1 tsunami recorded within 500 km.
Highest wave on record: 1.2 m (4 ft).
Year
Location
Cause
Max Wave
Deaths
Distance
1862
S. CALIFORNIA
Eruption + Earthquake
1.2 m
—
30 km
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
1 volcano within 200 km.
Closest: Salton Buttes (128 km).
Name
Type
Elevation
Last Eruption
Distance
Salton Buttes
Lava dome(s)
-40 m (-131 ft)
210
128 km
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km.
Largest: CEDAR (268,362 acres, 2003).
Year
Name
Acres Burned
Distance
2003
CEDAR
268,362
20 km
2007
WITCH
167,551
33 km
2007
HARRIS
90,443
22 km
2002
PINES
65,407
49 km
2003
PARADISE
55,995
45 km
2007
POOMACHA
47,496
55 km
2003
MINE/OTAY
37,232
21 km
2008
YELLOW
33,232
83 km
2022
FAIRVIEW
28,680
97 km
2020
INDIA
24,193
82 km
1993
CALIFORNIA
23,899
93 km
1994
PALM
21,040
100 km
2003
COYOTE
19,215
72 km
2007
AMMO FIRE
19,213
80 km
1993
GUEJITO
17,141
36 km
2006
HORSE
16,659
28 km
2020
VALLEY
16,517
21 km
1986
UNNAMED
16,390
87 km
1989
VAIL
15,632
69 km
2014
PULGAS
14,937
73 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
56°F (13°C)
2.6 in
Wettest
February
57°F (14°C)
2.4 in
March
58°F (14°C)
2.5 in
April
61°F (16°C)
1.1 in
May
64°F (18°C)
0.3 in
June
69°F (20°C)
0.1 in
Driest
July
75°F (24°C)
0.1 in
August
75°F (24°C)
0.2 in
Warmest
September
73°F (23°C)
0.3 in
October
68°F (20°C)
0.4 in
November
61°F (16°C)
1.5 in
December
56°F (13°C)
1.8 in
Coldest
Granite Hills has a seasonal temperature swing of 19°F / from 56°F in December to 75°F in August. Total annual precipitation is 13.1 inches, with January being the wettest month (2.6") and June the driest (0.1").