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Weather & Climate in Millsboro, DE
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Millsboro enjoys a temperate climate with an average annual temperature of 58°F (14°C). Winters average 37°F in January while summers reach 79°F in July. The area gets 293 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 43.9 inches. Air quality is rated Good with a median AQI of 41. The city sits at an elevation of 29 feet.
Temperature
37°F Jan (3°C)
79°F Jul (26°C)
| Annual Average | 57.6°F |
| 7% above US avg | |
| January Average | 37°F (3°C) |
| July Average | 79°F (26°C) |
| Sunny Days | 293 days/yr |
Geography
| Elevation | 29 ft (9 m) |
| Area | 4.0 sq mi (10.2 km²) |
| Population Density | 1,394/sq mi |
| Coordinates | 38.5887°N, 75.3096°W |
| Timezone | America/New_York |
| County | Sussex County County |
| Nearest Airport | Salisbury-Ocean City Wicomico Regional (SBY) 20 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 41.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 94.2 / 100 |
| Social Vulnerability | 70.4 / 100 |
| Community Resilience | 59.8 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Relatively High |
| Earthquake | Relatively Low |
| Wildfire | Relatively Low |
| Flood | Relatively Moderate |
| Hail | Relatively Low |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Very High |
| Lightning | Relatively High |
| Ice Storm | Relatively Moderate |
| Drought | Relatively Moderate |
| Cold Wave | Relatively High |
| Landslide | Very Low |
| Coastal Flood | Very High |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
7 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.2.
| Oct 23, 1990 | 3 km W of Hancocks Bridge, New Jersey | M3.2 | 104 km | 10 km |
| Jul 1, 2009 | 3 km ESE of Pennsville, New Jersey | M2.8 | 118 km | 5 km |
| Oct 28, 1994 | 1 km E of Mount Vernon, Maryland | M2.7 | 137 km | — |
| Jun 25, 2021 | 2 km SE of Woodlawn, Maryland | M2.6 | 145 km | 3 km |
| Jul 5, 1996 | 2 km NW of Chester Heights, Pennsylvania | M2.6 | 147 km | 18 km |
| Feb 9, 2023 | 29 km E of Greenbackville, Virginia | M2.6 | 66 km | 11 km |
| Feb 26, 1993 | 2 km SW of Marlton, New Jersey | M2.5 | 147 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Hurricane History
11 hurricanes (Category 1+) recorded within 500 km since 1980. Strongest on record: Category 3.
| Year | Name | Category | Max Wind | Closest |
| 2014 | Arthur | Category 2 | 92 mph | 193 km |
| 2012 | Sandy | Category 2 | 92 mph | 187 km |
| 2011 | Irene | Category 1 | 75 mph | 61 km |
| 2010 | Earl | Category 1 | 86 mph | 283 km |
| 2003 | Isabel | Category 1 | 75 mph | 297 km |
| 1999 | Floyd | Category 1 | — | 211 km |
| 1998 | Bonnie | Category 1 | 86 mph | 228 km |
| 1993 | Emily | Category 3 | 115 mph | 218 km |
| 1991 | Bob | Category 3 | 115 mph | 172 km |
| 1986 | Charley | Category 1 | 81 mph | 133 km |
| 1985 | Gloria | Category 2 | 98 mph | 74 km |
Source: NOAA IBTrACS (Category 1+, 1980–2026).
Tornado History
139 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 4 fatalities, 61 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Apr 1, 2023 | EF3 | 34 km | 14.3 mi | 1 |
| Apr 28, 2002 | EF3 | 88 km | 18.0 mi | 0 |
| Aug 4, 2020 | EF2 | 42 km | 1.3 mi | 0 |
| Aug 4, 2020 | EF2 | 60 km | 35.8 mi | 0 |
| Aug 4, 2020 | EF2 | 55 km | 3.8 mi | 0 |
| Apr 15, 2019 | EF2 | 25 km | 6.2 mi | 0 |
| Jul 23, 2017 | EF2 | 99 km | 2.4 mi | 0 |
| May 18, 1995 | EF2 | 68 km | 10.0 mi | 0 |
| Jul 31, 1992 | EF2 | 51 km | 4.0 mi | 0 |
| Jul 18, 1984 | EF2 | 33 km | 1.5 mi | 0 |
| Jul 21, 1983 | EF2 | 74 km | 1.0 mi | 2 |
| Jun 9, 1977 | EF2 | 51 km | 0.2 mi | 0 |
| Mar 21, 1976 | EF2 | 88 km | 0.2 mi | 0 |
| Aug 27, 1971 | EF2 | 49 km | 28.7 mi | 0 |
| Jul 30, 1971 | EF2 | 84 km | 8.3 mi | 0 |
| Jan 27, 1967 | EF2 | 53 km | 0.5 mi | 0 |
| May 6, 1956 | EF2 | 84 km | 0.2 mi | 0 |
| Aug 12, 1955 | EF2 | 22 km | 2.7 mi | 0 |
| Aug 4, 2022 | EF1 | 94 km | 2.3 mi | 0 |
| Jul 9, 2021 | EF1 | 85 km | 0.9 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Tsunami History
1 tsunami recorded within 500 km.
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1840 | PHILADELPHIA, PENNSYLVANIA | Earthquake | — | — | 135 km |
Source: NOAA/NCEI Historical Tsunami Database.
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: BESTPITCH (7,743 acres, 2017).
| Year | Name | Acres Burned | Distance |
| 2017 | BESTPITCH | 7,743 | 64 km |
| 2004 | RETAINING ECOLOGICAL HEALTH | 5,678 | 70 km |
| 2014 | BLACKWATER MARSH WUI BURNS FY14 | 5,433 | 69 km |
| 2005 | MARSH RX-FWS | 4,380 | 66 km |
| 2007 | GUINEA MARSH | 4,173 | 62 km |
| 2009 | DOCTORS CREEK | 3,686 | 62 km |
| 1999 | FB R O C I | 3,525 | 68 km |
| 2019 | MDBWR-FY19-RX-MDWHS SUPPORT | 3,197 | 68 km |
| 2011 | COMPARTMENT J | 2,775 | 68 km |
| 2005 | ISLAND CREEK | 2,729 | 62 km |
| 2004 | UNNAMED | 2,156 | 62 km |
| 1992 | UNNAMED | 2,038 | 63 km |
| 2005 | VEGETATION RESEARCH | 1,926 | 62 km |
| 2011 | THOROFARE | 1,850 | 63 km |
| 1987 | UNNAMED | 1,692 | 70 km |
| 2004 | ROBBINS FIRE | 1,612 | 70 km |
| 1988 | SLAU BCH 2 | 1,578 | 34 km |
| 2020 | SPLIT DITCH | 1,518 | 83 km |
| 2004 | BLACKWATER HAZARD FUEL REDUCTION | 1,518 | 73 km |
| 2014 | RAILROAD | 1,431 | 84 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 37°F (3°C) | 3.8 in | Coldest |
| February | 37°F (3°C) | 3.2 in | Driest |
| March | 45°F (7°C) | 4.2 in | |
| April | 54°F (12°C) | 3.4 in | |
| May | 63°F (17°C) | 3.8 in | |
| June | 72°F (22°C) | 3.4 in | |
| July | 79°F (26°C) | 3.9 in | Warmest |
| August | 75°F (24°C) | 4.3 in | Wettest |
| September | 69°F (21°C) | 3.6 in | |
| October | 58°F (14°C) | 3.4 in | |
| November | 49°F (9°C) | 3.2 in | |
| December | 40°F (4°C) | 3.6 in |
Millsboro has a seasonal temperature swing of 42°F / from 37°F in January to 79°F in July. Total annual precipitation is 43.6 inches, with August being the wettest month (4.3") and February the driest (3.2").