Temperature, precipitation, air quality, natural hazards, and monthly weather data.
South Yarmouth experiences four distinct seasons with an average annual temperature of 52°F (11°C). Winters average 32°F in January while summers reach 73°F in July. The area gets 275 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 44.7 inches. Air quality is rated Good with a median AQI of 37. The city sits at an elevation of 15 feet.
Temperature
32°F Jan (0°C)73°F Jul (23°C)
Annual Average
51.5°F
5% below US avg
January Average
32°F (0°C)
July Average
73°F (23°C)
Sunny Days
275 days/yr
Geography
Elevation
15 ft (5 m)
Area
7.8 sq mi (20.2 km²)
Population Density
1,673/sq mi
Coordinates
41.6671°N, 70.2008°W
Timezone
America/New_York
County
Barnstable County County
Nearest Airport
New Bedford Regional (EWB) 39 miles away
Precipitation & Snow
Annual Rainfall44.7"
18% above US avg
Wettest Month (Nov)4.41"
Driest Month (Jul)2.99"
Air Quality
AQI Median
37.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively Moderate
Risk Score
89.1 / 100
Social Vulnerability
34.5 / 100
Community Resilience
99.3 / 100
Hazard Breakdown
Tornado
Relatively Low
Hurricane
Relatively High
Earthquake
Relatively Low
Wildfire
Very Low
Flood
Relatively Moderate
Hail
Relatively Low
Strong Wind
Relatively Moderate
Heat Wave
Relatively Low
Winter Weather
Relatively Low
Lightning
Relatively High
Ice Storm
Relatively Low
Drought
Relatively Low
Cold Wave
Relatively Low
Landslide
Relatively Low
Coastal Flood
Very High
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
13 earthquakes (M2.5+) recorded within 150 km since 1990.
Strongest on record: M3.3.
Jan 12, 2015
0 km NE of Wauregan, Connecticut
M3.3
142 km
5 km
Mar 22, 1996
2 km NE of Bristol, Rhode Island
M3.1
87 km
12 km
Jan 10, 1999
2 km ENE of Merrimac, Massachusetts
M3.1
145 km
2 km
Mar 12, 2002
52 km E of Chatham, Massachusetts
M3.0
73 km
1 km
Jan 10, 1999
1 km NNE of Merrimac, Massachusetts
M3.0
146 km
2 km
Jul 22, 2003
72 km NNE of Provincetown, Massachusetts
M3.0
112 km
10 km
Jan 8, 1998
52 km ENE of Rockport, Massachusetts
M2.9
133 km
25 km
Oct 11, 1990
5 km NNE of The Pinehills, Massachusetts
M2.7
43 km
13 km
Oct 13, 1999
2 km E of Littleton Common, Massachusetts
M2.7
142 km
2 km
Apr 22, 1996
3 km NE of North Westport, Massachusetts
M2.6
72 km
5 km
Jan 13, 2015
2 km E of Wauregan, Connecticut
M2.6
140 km
9 km
Jun 7, 2002
3 km NNW of Hopedale, Massachusetts
M2.5
125 km
5 km
Jan 23, 1990
3 km NNW of Boxborough, Massachusetts
M2.5
146 km
5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Hurricane History
8 hurricanes (Category 1+) recorded within 500 km since 1980.
Strongest on record: Category 2.
Year
Name
Category
Max Wind
Closest
2021
Henri
Category 1
75 mph
261 km
2019
Dorian
Category 2
98 mph
284 km
2014
Arthur
Category 1
75 mph
169 km
2009
Bill
Category 1
86 mph
300 km
2008
Kyle
Category 1
86 mph
268 km
1996
Edouard
Category 1
81 mph
196 km
1991
Bob
Category 2
104 mph
104 km
1985
Gloria
Category 1
86 mph
217 km
Source: NOAA IBTrACS (Category 1+, 1980–2026).
Tornado History
38 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF2. Total: 1 fatality, 8 injuries.
Date
Rating
Distance
Path
Fatalities
Aug 28, 1970
EF2
59 km
1.0 mi
0
Nov 18, 1967
EF2
67 km
0.1 mi
0
Nov 21, 1956
EF2
98 km
0.1 mi
0
Dec 18, 1951
EF2
43 km
0.1 mi
0
Jun 26, 2024
EF1
92 km
0.6 mi
0
Aug 18, 2023
EF1
84 km
0.4 mi
0
Aug 8, 2023
EF1
54 km
0.9 mi
0
Jul 29, 2023
EF1
93 km
0.2 mi
0
Jul 23, 2019
EF1
8 km
5.5 mi
0
Jul 23, 2019
EF1
4 km
0.3 mi
0
Jul 23, 2019
EF1
10 km
2.8 mi
0
Oct 23, 2018
EF1
89 km
0.8 mi
0
Jul 23, 2008
EF1
91 km
4.3 mi
0
Jul 10, 1989
EF1
82 km
0.1 mi
0
Sep 16, 1986
EF1
74 km
0.1 mi
0
Aug 22, 1977
EF1
7 km
0.1 mi
0
Sep 6, 1973
EF1
96 km
1.1 mi
0
Aug 2, 1970
EF1
93 km
2.0 mi
0
Aug 9, 1968
EF1
58 km
1.0 mi
0
Aug 9, 1968
EF1
98 km
0.1 mi
0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
1 wildfire (100+ acres) recorded within 100 km.
Largest: NOMANS AERIAL RX (546 acres, 2008).
Year
Name
Acres Burned
Distance
2008
NOMANS AERIAL RX
546
69 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
32°F (0°C)
3.7 in
February
31°F (-0°C)
3.6 in
Coldest
March
38°F (3°C)
3.7 in
April
46°F (8°C)
3.8 in
May
55°F (13°C)
3.5 in
June
64°F (18°C)
3.2 in
July
73°F (23°C)
3.0 in
Warmest, Driest
August
70°F (21°C)
3.4 in
September
63°F (17°C)
3.5 in
October
53°F (12°C)
3.7 in
November
45°F (7°C)
4.4 in
Wettest
December
36°F (2°C)
4.3 in
South Yarmouth has a seasonal temperature swing of 42°F / from 31°F in February to 73°F in July. Total annual precipitation is 43.7 inches, with November being the wettest month (4.4") and July the driest (3.0").