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Weather & Climate in Ayer, MA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Ayer experiences four distinct seasons with an average annual temperature of 49°F (9°C). Winters average 25°F in January while summers reach 72°F in July. The area gets 246 sunny days per year, above the national average. Annual precipitation totals 43.4 inches. Air quality is rated Good with a median AQI of 37. The city sits at an elevation of 323 feet.
Temperature
25°F Jan (-4°C)
72°F Jul (22°C)
| Annual Average | 48.9°F |
| 9% below US avg | |
| January Average | 25°F (-4°C) |
| July Average | 72°F (22°C) |
| Sunny Days | 246 days/yr |
Geography
| Elevation | 323 ft (98 m) |
| Area | 1.4 sq mi (3.6 km²) |
| Population Density | 2,265/sq mi |
| Coordinates | 42.5622°N, 71.5848°W |
| Timezone | America/New_York |
| County | Middlesex County County |
| Nearest Airport | Worcester Regional (ORH) 25 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 37.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively High |
| Risk Score | 97.0 / 100 |
| Social Vulnerability | 15.8 / 100 |
| Community Resilience | 89.8 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Relatively High |
| Earthquake | Relatively Moderate |
| Wildfire | Relatively Low |
| Flood | Relatively High |
| Hail | Very Low |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively High |
| Ice Storm | Very High |
| Drought | Relatively Moderate |
| Cold Wave | Relatively High |
| Landslide | Very Low |
| Coastal Flood | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
35 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.7.
| Oct 16, 2012 | 5 km W of Hollis Center, Maine | M4.7 | 138 km | 16 km |
| Jan 27, 2025 | 9 km SE of York Harbor, Maine | M3.8 | 100 km | 11 km |
| Oct 2, 1994 | 6 km W of Hardwick, Massachusetts | M3.7 | 62 km | 10 km |
| Oct 6, 1992 | 1 km SW of Canterbury, New Hampshire | M3.4 | 85 km | 5 km |
| Jan 12, 2015 | 0 km NE of Wauregan, Connecticut | M3.3 | 94 km | 5 km |
| Jun 16, 2000 | 5 km NE of Granville, Massachusetts | M3.3 | 114 km | 10 km |
| Oct 2, 1994 | 1 km NW of Hardwick, Massachusetts | M3.3 | 57 km | 10 km |
| Sep 26, 2010 | 2 km SW of Canterbury, New Hampshire | M3.2 | 85 km | 5 km |
| Mar 22, 1996 | 2 km NE of Bristol, Rhode Island | M3.1 | 101 km | 12 km |
| Jan 10, 1999 | 2 km ENE of Merrimac, Massachusetts | M3.1 | 58 km | 2 km |
| Jan 27, 2000 | 3 km WNW of Fremont, New Hampshire | M3.0 | 59 km | 1 km |
| Jan 10, 1999 | 1 km NNE of Merrimac, Massachusetts | M3.0 | 57 km | 2 km |
| Jun 7, 2010 | 29 km SE of York Beach, Maine | M2.9 | 116 km | 10 km |
| Jan 8, 1998 | 52 km ENE of Rockport, Massachusetts | M2.9 | 130 km | 25 km |
| Apr 25, 2023 | 4 km SW of Center Sandwich, New Hampshire | M2.9 | 136 km | 8 km |
| Mar 9, 2008 | 25 km SE of York Beach, Maine | M2.8 | 112 km | 0 km |
| Sep 28, 2002 | 2 km N of Wilton, New Hampshire | M2.8 | 36 km | 5 km |
| Mar 23, 1992 | 5 km SE of Hill, New Hampshire | M2.8 | 104 km | 5 km |
| Mar 21, 2016 | 4 km ESE of Warner, New Hampshire | M2.8 | 80 km | 7 km |
| Feb 13, 1998 | 1 km SSE of Tamworth, New Hampshire | M2.7 | 146 km | 8 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Hurricane History
2 hurricanes (Category 1+) recorded within 500 km since 1980. Strongest on record: Category 2.
| Year | Name | Category | Max Wind | Closest |
| 1991 | Bob | Category 2 | 104 mph | 89 km |
| 1985 | Gloria | Category 1 | 86 mph | 124 km |
Source: NOAA IBTrACS (Category 1+, 1980–2026).
Tornado History
229 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 100 fatalities, 1,346 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Jun 9, 1953 | EF4 | 49 km | 34.9 mi | 94 |
| Jun 22, 1981 | EF3 | 37 km | 7.1 mi | 0 |
| Sep 29, 1974 | EF3 | 29 km | 0.1 mi | 0 |
| Sep 13, 1971 | EF3 | 93 km | 0.5 mi | 0 |
| Oct 3, 1970 | EF3 | 55 km | 35.4 mi | 1 |
| May 20, 1963 | EF3 | 56 km | 14.0 mi | 0 |
| Jun 9, 1953 | EF3 | 46 km | 28.0 mi | 0 |
| Jun 9, 1953 | EF3 | 68 km | 1.5 mi | 0 |
| Aug 18, 2023 | EF2 | 85 km | 9.1 mi | 0 |
| Jul 28, 2014 | EF2 | 50 km | 1.9 mi | 0 |
| Jul 24, 2008 | EF2 | 69 km | 50.5 mi | 1 |
| Jul 11, 2006 | EF2 | 67 km | 2.9 mi | 0 |
| May 21, 2006 | EF2 | 72 km | 0.1 mi | 0 |
| Jul 6, 1999 | EF2 | 85 km | 7.5 mi | 0 |
| May 31, 1998 | EF2 | 60 km | 0.5 mi | 0 |
| Jul 3, 1997 | EF2 | 48 km | 2.0 mi | 0 |
| Aug 7, 1986 | EF2 | 89 km | 4.0 mi | 0 |
| Aug 10, 1979 | EF2 | 52 km | 9.7 mi | 2 |
| May 3, 1976 | EF2 | 87 km | 1.0 mi | 0 |
| Aug 27, 1972 | EF2 | 75 km | 1.0 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
1 wildfire (100+ acres) recorded within 100 km. Largest: THE RANGE (760 acres, 2005).
| Year | Name | Acres Burned | Distance |
| 2005 | THE RANGE | 760 | 9 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 25°F (-4°C) | 3.7 in | Coldest |
| February | 25°F (-4°C) | 3.4 in | Driest |
| March | 34°F (1°C) | 3.9 in | |
| April | 45°F (7°C) | 3.9 in | |
| May | 56°F (13°C) | 3.7 in | |
| June | 64°F (18°C) | 3.7 in | |
| July | 72°F (22°C) | 3.7 in | Warmest |
| August | 69°F (21°C) | 3.8 in | |
| September | 61°F (16°C) | 3.5 in | |
| October | 50°F (10°C) | 3.9 in | |
| November | 41°F (5°C) | 4.5 in | Wettest |
| December | 29°F (-1°C) | 4.0 in |
Ayer has a seasonal temperature swing of 48°F / from 25°F in January to 72°F in July. Total annual precipitation is 45.6 inches, with November being the wettest month (4.5") and February the driest (3.4").