Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Heiwadai enjoys a temperate climate with an average annual temperature of 62°F (17°C). Winters average 39°F in January while summers reach 84°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 51.6 inches (wetter than the 38-inch national average). The area receives 5.4 inches of snow annually. The city sits at an elevation of 121 feet.
Temperature
39°F Jan (4°C)84°F Jul (29°C)
Annual Average
62.2°F
15% above US avg
January Average
39°F (4°C)
July Average
84°F (29°C)
Sunny Days
293 days/yr
Geography
Elevation
121 ft (37 m)
Area
20.3 sq mi (52.7 km²)
Population Density
677/sq mi
Coordinates
35.7576°N, 139.6598°W
Timezone
Asia/Tokyo
Precipitation & Snow
Annual Rainfall51.6"
36% above US avg
Snowfall5.4"
Wettest Month (Sep)8.07"
Driest Month (Jan)1.61"
Air Quality
Earthquake History
2,395 earthquakes (M2.5+) recorded within 150 km since 1990.
Strongest on record: M7.9.
Mar 11, 2011
47 km E of ?arai, Japan
M7.9
143 km
43 km
Feb 20, 1990
28 km E of Shimoda, Japan
M6.4
123 km
14 km
Jun 1, 1990
near the east coast of Honshu, Japan
M6.3
67 km
67 km
Jun 3, 2000
6 km SE of Narut?, Japan
M6.2
76 km
62 km
Apr 21, 2011
6 km WNW of T?gane, Japan
M6.2
62 km
43 km
Sep 11, 1996
23 km SSE of Hasaki, Japan
M6.2
119 km
55 km
Apr 11, 2011
23 km SE of T?gane, Japan
M6.2
91 km
15 km
May 26, 2023
12 km SE of Narutō, Japan
M6.1
83 km
42 km
Aug 5, 1990
43 km E of ?arai, Japan
M6.1
141 km
27 km
May 4, 2014
31 km ESE of It?, Japan
M6.0
97 km
153 km
Mar 15, 2011
6 km NNW of Fujinomiya, Japan
M6.0
112 km
9 km
Mar 14, 2012
5 km SE of Asahi, Japan
M6.0
94 km
10 km
Aug 6, 1991
19 km E of Hasaki, Japan
M6.0
125 km
29 km
Mar 11, 2011
4 km ESE of Hasaki, Japan
M6.0
110 km
48 km
Jul 20, 2000
31 km ESE of Hitachi, Japan
M6.0
145 km
47 km
Apr 3, 2004
37 km ESE of Hitachi, Japan
M6.0
142 km
31 km
Jun 24, 2020
36 km SE of Hasaki, Japan
M5.9
132 km
29 km
Jul 23, 2005
9 km WSW of Ichihara, Japan
M5.9
41 km
61 km
Apr 10, 2005
near the east coast of Honshu, Japan
M5.9
69 km
43 km
Jan 15, 2007
15 km WSW of Heda, Japan
M5.9
134 km
170 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Hurricane History
36 hurricanes (Category 1+) recorded within 500 km since 1980.
Strongest on record: Category 3.
Year
Name
Category
Max Wind
Closest
2024
Ampil
Category 3
98 mph
218 km
2024
Jebi
Category 1
75 mph
254 km
2019
Faxai
Category 3
98 mph
36 km
2019
Hagibis
Category 2
92 mph
29 km
2018
Jongdari
Category 2
86 mph
197 km
2018
Shanshan
Category 1
81 mph
169 km
2016
Lionrock
Category 1
75 mph
266 km
2016
Mindulle
Category 1
75 mph
163 km
2014
Phanfone
Category 1
81 mph
149 km
2011
Roke
Category 2
92 mph
44 km
2009
Krovanh
Category 1
69 mph
252 km
2007
Fitow
Category 1
81 mph
45 km
2005
Saola
Category 2
86 mph
276 km
2005
Mawar
Category 2
81 mph
45 km
2004
Ma-on
Category 3
92 mph
22 km
2003
Choi-wan
Category 3
81 mph
293 km
2002
Higos
Category 2
86 mph
27 km
2002
Phanfone
Category 1
75 mph
300 km
2001
Vipa
Category 1
63 mph
264 km
2001
Danas
Category 1
81 mph
22 km
Source: NOAA IBTrACS (Category 1+, 1980–2026).
Tsunami History
19 tsunamis recorded within 500 km.
Highest wave on record: 13.0 m (43 ft).
Year
Location
Cause
Max Wave
Deaths
Distance
1923
SAGAMI BAY
Earthquake
13.0 m
105,385
75 km
1703
OFF SW BOSO PENINSULA
Earthquake
11.7 m
5,233
118 km
1495
KAMAKURA, SAGAMI BAY, TOKAIDO
Earthquake
5.0 m
200
75 km
1732
KUJUKURI BEACH, JAPAN
Earthquake
2.0 m
—
120 km
1670
BOSO, JAPAN
Earthquake
2.0 m
—
125 km
1433
OFF IZU-OSHIMA
Earthquake
2.0 m
—
97 km
1980
HONSHU ISLAND
Earthquake
0.6 m
—
114 km
1978
TOKAIDO
Earthquake
0.4 m
25
112 km
1923
RYUKYU ISLANDS
Earthquake
0.3 m
—
107 km
1896
KASHIMA, JAPAN
Earthquake
0.3 m
—
146 km
1990
JAPAN
Earthquake
0.2 m
—
123 km
1855
TOKAIDO
Earthquake
—
6,757
17 km
1782
ODAWARA, SAGAMI BAY
Eruption + Earthquake
—
—
73 km
1642
BOSO, JAPAN
Earthquake
—
—
105 km
1633
SAGAMI BAY
Earthquake
—
150
75 km
1602
BOSO, JAPAN
Eruption + Earthquake
—
—
106 km
1257
SAGAMI BAY, JAPAN
Earthquake
—
—
64 km
1241
KAMAKURA, SAGAMI BAY
Earthquake
—
—
66 km
818
TOKAIDO
Eruption + Earthquake
—
—
70 km
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
15 volcanoes within 200 km.
Closest: Hakoneyama (82 km).
Name
Type
Elevation
Last Eruption
Distance
Hakoneyama
Complex
1,438 m (4,718 ft)
2015
82 km
Fujisan
Stratovolcano
3,776 m (12,388 ft)
1708
95 km
Akagisan
Stratovolcano
1,828 m (5,997 ft)
Unknown
99 km
Izu-Tobu
Pyroclastic cone(s)
1,406 m (4,613 ft)
1989
108 km
Harunasan
Stratovolcano
1,449 m (4,754 ft)
550
108 km
Nantaisan
Stratovolcano
2,486 m (8,156 ft)
-9540
113 km
Omanago Group
Lava dome(s)
2,341 m (7,680 ft)
-3050
116 km
Izu-Oshima
Stratovolcano
758 m (2,487 ft)
1990
117 km
Nikko-Shiranesan
Shield
2,578 m (8,458 ft)
1952
119 km
Asamayama
Complex
2,568 m (8,425 ft)
2019
125 km
Yokodake
Stratovolcano(es)
2,480 m (8,136 ft)
1200
126 km
Takaharayama
Stratovolcano
1,795 m (5,889 ft)
-4570
128 km
Hiuchigatake
Stratovolcano
2,356 m (7,730 ft)
1544
137 km
Kusatsu-Shiranesan
Stratovolcano(es)
2,165 m (7,103 ft)
2018
140 km
Toshima
Stratovolcano
508 m (1,667 ft)
-4550
142 km
Source: Smithsonian Institution Global Volcanism Program (GVP).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
39°F (4°C)
1.6 in
Coldest, Driest
February
41°F (5°C)
2.2 in
March
47°F (8°C)
3.7 in
April
57°F (14°C)
4.5 in
May
65°F (18°C)
5.4 in
June
71°F (22°C)
7.3 in
July
84°F (29°C)
6.4 in
Warmest
August
80°F (27°C)
6.9 in
September
73°F (23°C)
8.1 in
Wettest
October
63°F (17°C)
6.7 in
November
53°F (12°C)
3.2 in
December
44°F (7°C)
1.6 in
Heiwadai has a seasonal temperature swing of 45°F / from 39°F in January to 84°F in July. Total annual precipitation is 57.5 inches, with September being the wettest month (8.1") and January the driest (1.6").