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Calvert County Climate

Calvert County, Maryland

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec58.9°AVG °F

Avg Annual Temp

58.9°F

Annual Precip

Annual Snowfall

Extreme Heat Days

31

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Growing Season & Gardening

USDA Hardiness Zone

7b

Minimum winter temperature range for plant survival

Growing Degree Days

4,559

Excellent for heat-loving crops

Last spring frost (32°F): 03/22
First fall frost (32°F): 11/26

Seasonal Overview

Comfort ZoneSpring46°66°0.0"Summer76°80°0.0"Fall51°72°0.0"Winter38°42°0.0"20°40°60°80°100°

National Comparison

Warmer than 67% of US counties
More seasonal variation than 48% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Calvert County

Climate Verdict

Calvert County has a mild, with an average annual temperature of 58.9°F, occasional hot days — 30.7 per year above 90°F. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 37.7°F. summers are hot, with July averaging 80.3°F. The 43°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

The moderate temperatures support hiking, cycling, and camping comfortably in spring, summer, and fall.

Regional Context

Calvert County is 3.0°F warmer than the Maryland statewide average of 55.9°F.

Climate Profile

About Calvert County Weather

One of Maryland's warmest spots

Calvert County averages 58.9°F annually, placing it well above the national median temperature. This Southern Maryland peninsula enjoys a mild, humid subtropical climate.

Leading the state in warmth

The county is 3 degrees warmer than the Maryland state average of 55.9°F. It is consistently one of the warmest counties in Maryland due to its southern latitude and bay influence.

Warmer than northern bay counties

Calvert is warmer than Anne Arundel and significantly warmer than central Maryland counties like Carroll. Its July average of 80.3°F represents some of the highest summer temperatures in the region.

Hot summers and mild winters

Residents experience 31 days of extreme heat annually, with July averaging 80.3°F. Winters are among the state's mildest, featuring a January average of 37.7°F.

Prioritize summer cooling needs

The primary climate challenge is the 31 days of 90-degree weather, requiring efficient HVAC systems. While snowfall data is limited, the mild 39.7°F winter average suggests minimal snow disruption.

Frequently Asked Questions

What is the average temperature in Calvert County?
The average annual temperature in Calvert County, MD is 58.9°F, based on NOAA 30-year climate normals (1991-2020).
How hot does Calvert County get in summer?
The average summer temperature (June-August) in Calvert County is 78.2°F. The county experiences an average of 31 days per year above 90°F.
How cold are winters in Calvert County?
The average winter temperature (December-February) in Calvert County is 39.7°F. January, typically the coldest month, averages 37.7°F.

Track your own weather in Calvert County

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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.

Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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