Weather & Climate in St. Mary's, CO

Temperature, precipitation, air quality, natural hazards, and monthly weather data.

St. Mary's has a cool climate with an average annual temperature of 42°F (6°C). Winters average 26°F in January while summers reach 63°F in July. 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 18.3 inches (drier than the 38-inch national average). The area receives 105.9 inches of snow annually, making winter weather a significant factor for residents. Air quality is rated Good with a median AQI of 41. The city sits at an elevation of 10,051 feet.

Temperature

26°F Jan (-3°C) 63°F Jul (17°C)

Annual Average	42.2°F
	22% below US avg
January Average	26°F (-3°C)
July Average	63°F (17°C)
Sunny Days	330 days/yr

Geography

Elevation	10,051 ft (3,064 m)
Area	1.5 sq mi (3.8 km²)
Population Density	90/sq mi
Coordinates	39.8165°N, 105.6471°W
Timezone	America/Denver
County	Gilpin County County
Nearest Airport	Denver International (DEN) 52 miles away

Precipitation & Snow

Annual Rainfall 18.3"

52% below US avg

Snowfall 105.9"

Wettest Month (Jul) 2.28"

Driest Month (Feb) 1.14"

Air Quality

AQI Median	41.0
Rating	Good

Natural Hazard Risk

Overall Risk	Very Low
Risk Score	6.4 / 100
Social Vulnerability	12.8 / 100
Community Resilience	79.3 / 100

Hazard Breakdown

Tornado	Very Low
Earthquake	Very Low
Wildfire	Relatively Low
Flood	Very Low
Hail	Relatively Low
Strong Wind	Very Low
Heat Wave	No Rating
Winter Weather	Relatively Low
Lightning	Relatively Low
Ice Storm	Very Low
Drought	No Rating
Cold Wave	Very Low
Landslide	Relatively Low
Volcano	Very Low
Avalanche	Relatively Low

Source: FEMA National Risk Index v1.20 (Dec 2025)

Earthquake History

49 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.0.

Aug 9, 2001	11 km NNE of Chacra, Colorado	M4.0	149 km	5 km
Dec 25, 1994	9 km NE of Larkspur, Colorado	M4.0	93 km	10 km
Jun 6, 2011	17 km NNW of Oak Creek, Colorado	M3.5	135 km	5 km
Dec 23, 1995	7 km WNW of Rock Creek Park, Colorado	M3.5	136 km	5 km
Apr 10, 2011	12 km N of Oak Creek, Colorado	M3.4	127 km	5 km
Aug 21, 2012	12 km SSW of Gypsum, Colorado	M3.4	119 km	5 km
Jan 18, 1997	8 km SE of Westcreek, Colorado	M3.3	93 km	5 km
Jun 1, 2014	9 km NNW of Kersey, Colorado	M3.2	114 km	1 km
Jul 22, 2001	6 km WNW of Woodland Park, Colorado	M3.1	99 km	5 km
Jul 8, 1993	9 km ENE of Aspen, Colorado	M3.1	113 km	5 km
Sep 2, 2024	21 km NW of Steamboat Springs, Colorado	M3.1	147 km	2 km
Feb 1, 2019	3 km NW of Glenwood Springs, Colorado	M3.1	148 km	2 km
Feb 7, 2000	19 km NE of Steamboat Springs, Colorado	M3.0	123 km	5 km
Sep 12, 1990	13 km NW of Silverthorne, Colorado	M3.0	50 km	5 km
Jan 19, 1997	8 km SE of Westcreek, Colorado	M2.9	93 km	5 km
Feb 26, 2008	29 km WNW of Westcreek, Colorado	M2.9	62 km	2 km
Jan 1, 2003	6 km SE of Aspen, Colorado	M2.9	121 km	5 km
Mar 30, 2019	7 km NE of Greeley, Colorado	M2.9	112 km	6 km
May 1, 2009	21 km NW of Dotsero, Colorado	M2.9	135 km	5 km
Oct 27, 2013	17 km NNW of Oak Creek, Colorado	M2.8	135 km	1 km

Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.

Tornado History

362 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 1 fatality, 151 injuries.

Date	Rating	Distance	Path	Fatalities
Jun 4, 2015	EF3	68 km	6.7 mi	0
May 22, 2008	EF3	89 km	38.7 mi	1
Jun 15, 1988	EF3	62 km	2.5 mi	0
Jun 12, 1982	EF3	95 km	3.0 mi	0
May 18, 1975	EF3	78 km	4.1 mi	0
Jun 7, 2021	EF2	73 km	7.5 mi	0
Jun 8, 2014	EF2	95 km	6.0 mi	0
Jun 15, 1988	EF2	62 km	0.5 mi	0
Jun 5, 1988	EF2	51 km	0.5 mi	0
Jun 5, 1988	EF2	61 km	2.0 mi	0
Jul 2, 1987	EF2	79 km	1.0 mi	0
Jun 20, 1987	EF2	88 km	1.0 mi	0
Jun 8, 1986	EF2	89 km	2.0 mi	0
Jun 8, 1986	EF2	65 km	1.1 mi	0
Jul 19, 1985	EF2	74 km	0.5 mi	0
May 18, 1984	EF2	97 km	5.0 mi	0
May 18, 1984	EF2	90 km	5.0 mi	0
Jun 3, 1981	EF2	57 km	2.3 mi	0
Jun 3, 1981	EF2	52 km	0.1 mi	0
Oct 15, 1980	EF2	43 km	1.5 mi	0

Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).

Wildfire History

20 wildfires (100+ acres) recorded within 100 km. Largest: CAMERON PEAK (208,910 acres, 2020).

Year	Name	Acres Burned	Distance
2020	CAMERON PEAK	208,910	90 km
2020	EAST TROUBLESOME	188,924	55 km
2002	HAYMAN	129,417	73 km
2012	HIGH PARK	90,769	97 km
2018	SILVER CREEK	20,725	93 km
2020	WILLIAMS FORK	14,679	29 km
2018	WESTON PASS	13,169	93 km
1996	BUFFALO CREEK	11,690	59 km
2000	BOBCAT	10,444	79 km
2020	CALWOOD	9,836	46 km
2000	HIGH MEADOWS	9,607	52 km
2001	MVD PSFRXASST 4	7,375	78 km
2021	MARSHALL	6,286	43 km
2010	FOURMILE CANYON	5,865	34 km
2002	BIG ELK	4,348	56 km
2012	LOWER NORTH FORK FIRE	3,436	57 km
2003	OVERLAND	3,232	43 km
2009	OLD STAGE	3,160	44 km
2011	CRYSTAL FIRE	2,855	87 km
2002	SCHOONOVER	2,821	74 km

Source: NIFC/IRWIN Wildfire Records (100+ acres).

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	26°F (-3°C)	1.3 in
February	24°F (-4°C)	1.1 in	Coldest, Driest
March	27°F (-3°C)	1.5 in
April	33°F (0°C)	1.9 in
May	43°F (6°C)	2.1 in
June	52°F (11°C)	1.8 in
July	63°F (17°C)	2.3 in	Warmest, Wettest
August	56°F (13°C)	2.2 in
September	49°F (10°C)	1.6 in
October	40°F (5°C)	1.2 in
November	29°F (-2°C)	1.3 in
December	25°F (-4°C)	1.4 in

St. Mary's has a seasonal temperature swing of 39°F / from 24°F in February to 63°F in July. Total annual precipitation is 19.6 inches, with July being the wettest month (2.3") and February the driest (1.1").

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