Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Fortuna has a cool climate with an average annual temperature of 38°F (4°C). Winters average 7°F in January while summers reach 67°F in July. The area gets 274 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 15.3 inches (drier than the 38-inch national average). The area receives 36.5 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 38. The city sits at an elevation of 2,206 feet.
Temperature
7°F Jan (-14°C)67°F Jul (19°C)
Annual Average
38.4°F
29% below US avg
January Average
7°F (-14°C)
July Average
67°F (19°C)
Sunny Days
274 days/yr
Geography
Elevation
2,206 ft (672 m)
Area
1.0 sq mi (2.6 km²)
Population Density
73/sq mi
Coordinates
48.9097°N, 103.7791°W
Timezone
America/Chicago
County
Divide County County
Nearest Airport
Williston Basin International (XWA) 45 miles away
Precipitation & Snow
Annual Rainfall15.3"
60% below US avg
Snowfall36.5"
Wettest Month (Jun)2.52"
Driest Month (Feb)0.35"
Air Quality
AQI Median
38.0
Rating
Good
Natural Hazard Risk
Overall Risk
Very Low
Risk Score
5.8 / 100
Social Vulnerability
63.7 / 100
Community Resilience
17.0 / 100
Hazard Breakdown
Tornado
Very Low
Earthquake
Very Low
Wildfire
Very Low
Flood
Very Low
Hail
Relatively Low
Strong Wind
Very Low
Heat Wave
Very Low
Winter Weather
Relatively Moderate
Lightning
Very Low
Ice Storm
Relatively Moderate
Drought
Relatively Low
Cold Wave
Relatively Low
Landslide
Very Low
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
4 earthquakes (M2.5+) recorded within 150 km since 1990.
Strongest on record: M3.8.
Feb 25, 2014
23 km N of Brockton, Montana
M3.8
101 km
5 km
Jul 29, 1998
16 km WNW of Froid, Montana
M3.8
91 km
5 km
Nov 11, 1998
10 km SW of Grenora, North Dakota
M3.5
44 km
5 km
Sep 28, 2012
22 km ESE of Williston, North Dakota
M3.3
101 km
5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
66 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF3. Total: 2 fatalities, 1 injury.
Date
Rating
Distance
Path
Fatalities
Jul 26, 2010
EF3
94 km
18.0 mi
2
Jul 11, 1974
EF3
94 km
0.1 mi
0
Jun 14, 1950
EF3
1 km
23.7 mi
0
Jun 27, 1982
EF2
85 km
0.4 mi
0
Jun 5, 1976
EF2
82 km
2.0 mi
0
Jul 2, 1971
EF2
70 km
10.0 mi
0
Sep 21, 1969
EF2
91 km
1.0 mi
0
Jun 13, 1953
EF2
87 km
0.1 mi
0
Jul 9, 2018
EF1
57 km
2.1 mi
0
Jul 8, 2009
EF1
82 km
9.7 mi
0
Jun 11, 2007
EF1
25 km
3.0 mi
0
Jul 18, 2003
EF1
35 km
2.0 mi
0
Jul 21, 1999
EF1
93 km
1.0 mi
0
Jul 2, 1990
EF1
13 km
0.1 mi
0
Jul 30, 1984
EF1
94 km
0.1 mi
0
Jun 27, 1975
EF1
74 km
0.1 mi
0
Aug 5, 1969
EF1
72 km
0.1 mi
0
Aug 5, 1968
EF1
62 km
0.1 mi
0
Jul 7, 1965
EF1
94 km
2.5 mi
0
Aug 18, 1962
EF1
2 km
0.1 mi
0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km.
Largest: WILLIAMS CO WILDLAND FIRE (67,150 acres, 2024).
Year
Name
Acres Burned
Distance
2024
WILLIAMS CO WILDLAND FIRE
67,150
68 km
1988
BAINVILLE
12,790
96 km
2016
FLAGSTAFF HILL
9,129
86 km
1999
OUTLOOK
6,292
74 km
1999
ANTELOPE
5,118
55 km
2021
13 MILE FIRE
2,585
67 km
2007
W-RX-F SANDHILLS SUB UNIT B
2,381
67 km
2018
MTMLR-FY18-RX-WUI DEEP LAKE
2,088
65 km
2021
HIGHWAY 16 NORTH
2,069
94 km
2022
MTMLR-FY22-RX-BRIDGERMAN
1,852
64 km
2008
NORTH SOUTH LAKE CREEK SU A
1,367
58 km
2011
W-RX-F EAST ML BRIGERMANN
1,197
66 km
1992
N ELBOW L
1,189
98 km
1995
N ELBOW LAKE
1,166
98 km
1986
N ELBOW
1,164
98 km
1998
N ELBOW LAKE
1,160
98 km
2009
NORTH ELBOW LAKE N 1 2
1,148
98 km
2023
MTMLR-HFR-FY23-RX
1,128
83 km
2007
H-RX-F BRIGERMANN 2007
1,043
65 km
2022
MTMLR-FY22-RX-NORTHSHORE
1,015
66 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
7°F (-14°C)
0.4 in
Coldest
February
14°F (-10°C)
0.4 in
Driest
March
26°F (-3°C)
0.6 in
April
41°F (5°C)
1.1 in
May
54°F (12°C)
2.1 in
June
64°F (18°C)
2.5 in
Wettest
July
67°F (19°C)
2.3 in
August
67°F (20°C)
1.8 in
Warmest
September
56°F (13°C)
1.5 in
October
43°F (6°C)
0.8 in
November
25°F (-4°C)
0.4 in
December
12°F (-11°C)
0.4 in
Fortuna has a seasonal temperature swing of 60°F / from 7°F in January to 67°F in August. Total annual precipitation is 14.3 inches, with June being the wettest month (2.5") and February the driest (0.4").