Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Heidelberg has a warm climate with an average annual temperature of 75°F (24°C). Winters average 61°F in January while summers reach 86°F in July. The area gets 312 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 25.7 inches (drier than the 38-inch national average). Air quality is rated Good with a median AQI of 42. The city sits at an elevation of 59 feet.
Temperature
61°F Jan (16°C)86°F Jul (30°C)
Annual Average
75.0°F
39% above US avg
January Average
61°F (16°C)
July Average
86°F (30°C)
Sunny Days
312 days/yr
Geography
Elevation
59 ft (18 m)
Area
2.6 sq mi (6.8 km²)
Population Density
841/sq mi
Coordinates
26.1828°N, 97.8859°W
Timezone
America/Chicago
County
Cameron County County
Nearest Airport
Valley International (HRL) 15 miles away
Precipitation & Snow
Annual Rainfall25.7"
32% below US avg
Wettest Month (Sep)4.96"
Driest Month (Mar)0.67"
Air Quality
AQI Median
42.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively High
Risk Score
97.3 / 100
Social Vulnerability
91.7 / 100
Community Resilience
6.3 / 100
Hazard Breakdown
Tornado
Relatively Moderate
Hurricane
Very High
Earthquake
Very Low
Wildfire
Relatively Low
Flood
Relatively Moderate
Hail
Relatively High
Strong Wind
Relatively High
Heat Wave
Relatively High
Winter Weather
Relatively High
Lightning
Relatively High
Ice Storm
Relatively High
Drought
Relatively Moderate
Cold Wave
Very High
Landslide
Very Low
Coastal Flood
Relatively Moderate
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
1 earthquake (M2.5+) recorded within 150 km since 1990.
Strongest on record: M4.0.
Feb 11, 2014
31 km SSE of China, Mexico
M4.0
150 km
41 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Hurricane History
13 hurricanes (Category 1+) recorded within 500 km since 1980.
Strongest on record: Category 5.
Year
Name
Category
Max Wind
Closest
2024
Beryl
Category 1
92 mph
267 km
2021
Nicholas
Category 1
75 mph
262 km
2020
Hanna
Category 1
92 mph
48 km
2017
Harvey
Category 4
132 mph
187 km
2010
Alex
Category 2
109 mph
218 km
2008
Dolly
Category 2
98 mph
36 km
2005
Emily
Category 3
127 mph
144 km
2003
Claudette
Category 1
92 mph
286 km
2003
Erika
Category 1
75 mph
110 km
1999
Bret
Category 4
144 mph
82 km
1988
Gilbert
Category 4
132 mph
199 km
1983
Barry
Category 1
81 mph
95 km
1980
Allen
Category 5
161 mph
37 km
Source: NOAA IBTrACS (Category 1+, 1980–2026).
Tornado History
130 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF3. Total: 1 fatality, 39 injuries.
Date
Rating
Distance
Path
Fatalities
Mar 15, 1983
EF3
46 km
6.1 mi
0
May 12, 1969
EF3
30 km
0.1 mi
0
May 12, 1969
EF3
21 km
0.1 mi
0
Apr 19, 1965
EF3
73 km
1.5 mi
0
May 5, 1991
EF2
70 km
1.0 mi
0
Aug 9, 1980
EF2
41 km
4.6 mi
0
May 24, 1970
EF2
37 km
25.5 mi
0
May 12, 1969
EF2
53 km
0.1 mi
0
Apr 26, 1967
EF2
58 km
40.2 mi
0
Jun 1, 1962
EF2
34 km
1.0 mi
0
Jan 26, 1950
EF2
81 km
4.7 mi
0
May 13, 2023
EF1
63 km
0.5 mi
1
Oct 30, 2015
EF1
29 km
0.7 mi
0
Jun 30, 2011
EF1
32 km
0.4 mi
0
Jul 16, 2007
EF1
34 km
1.0 mi
0
Apr 30, 2003
EF1
57 km
0.3 mi
0
May 21, 2001
EF1
44 km
0.2 mi
0
May 21, 2001
EF1
45 km
0.1 mi
0
Apr 4, 1997
EF1
48 km
0.5 mi
0
Jun 14, 1994
EF1
61 km
0.5 mi
0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
17 wildfires (100+ acres) recorded within 100 km.
Largest: BURNS RANCH FIRE (58,395 acres, 2008).
Year
Name
Acres Burned
Distance
2008
BURNS RANCH FIRE
58,395
67 km
2022
HAYFIELD SOUTH
11,038
66 km
2021
KING
9,793
82 km
2022
VIB
7,817
84 km
2022
POLO
5,571
73 km
2008
ENCINO
3,979
82 km
2011
KING RANCH
3,075
62 km
2009
SAN CARLOS
2,849
80 km
2010
ENCINITOS RANCH
1,967
80 km
2022
755
1,846
85 km
2011
ENCINITOS
1,748
80 km
2022
DEER
1,657
91 km
2009
STILLMAN
1,466
55 km
2023
ELECTRIC SLIDE
1,410
87 km
2008
SAN RAFAEL RANCH
1,407
95 km
2008
281
1,308
85 km
2022
LA PALOMA
1,214
73 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
61°F (16°C)
1.5 in
Coldest
February
62°F (17°C)
1.5 in
March
69°F (21°C)
0.7 in
Driest
April
75°F (24°C)
1.4 in
May
79°F (26°C)
3.0 in
June
83°F (28°C)
2.9 in
July
86°F (30°C)
2.1 in
Warmest
August
85°F (29°C)
2.5 in
September
82°F (28°C)
5.0 in
Wettest
October
75°F (24°C)
2.3 in
November
67°F (20°C)
1.3 in
December
61°F (16°C)
1.3 in
Heidelberg has a seasonal temperature swing of 25°F / from 61°F in January to 86°F in July. Total annual precipitation is 25.4 inches, with September being the wettest month (5.0") and March the driest (0.7").