Climate - Sendai (Japan)

In Sendai, a Japanese city in the north-east of Honshu Island, in Miyagi Prefecture, the climate is temperate humid, with cold winters and warm, rainy summers. Like the rest of Japan, the city is affected by the monsoon circulation: in winter, the northwest cold currents will prevail, while in summer, they will be replaced by hot and humid currents of tropical origin (although to a lesser extent than in central and southern Japan).
In winter, temperatures are low: in January and February, lows are slightly below freezing (0 °C or 32 °F) and highs a few degrees above. Waves of intense cold are rare: usually, the temperature does not drop below -5 °C (23 °F), although the cold is fairly constant and the air is humid.
However, the coldest record in the city is -10 °C (14 °F), recorded in January 1967, while at the airport the temperature dropped to -11 °C (12 °F) in February 1990 and 1991.
Despite the fact that the city is located on the east coast, snow is quite common, and sometimes abundant. An average of about 60 centimeters (23.5 inches) of snow fals per year, distributed in 60 days (in most cases, however, it is sleet or light snow).
In summer, average temperatures are not too high, actually, during periods of bad weather, there is a cool northeast wind called Yamase. However, in this season, sunny periods, with hot and humid conditions, can occur (though more rarely than in Tokyo), and alternate with periods of bad weather, with wind and rain.
Here are the average temperatures.

Precipitation is quite abundant, in fact, it amounts to 1,275 millimeters (50 inches) per year; winter is the driest season (at least in quantity, as drizzle or sleet often falls), while summer is the rainiest season because of the summer monsoon. Here is the average precipitation.

The cherry blossoming (Sakura) in Sendai occurs around April 13th, about two or three weeks later than in Tokyo.
The amount of sunshine in Sendai is not exceptional: it is pretty good in winter (considering that the days are shorter), it reaches a relative maximum in spring, and then it declines in summer because of the monsoon. Here are the average sunshine hours per day.



The sea in Sendai, cold in winter, becomes acceptable for swimming in August and September, while it is still cool in July, as you can see in the following table.

From June to October (but especially from August to early October), Sendai may be affected by typhoons, though typically with less frequency and intensity than in southern Japan.

Sendai - Weather by month

Based on the period 1991-2020

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In January, the coldest month of the year, the weather in Sendai is usually cold. The average temperature is of 2.2 °C (36 °F), with a minimum of -1.3 °C (29.7 °F) and a maximum of 5.6 °C (42.1 °F).
On the coldest nights of the month, the temperature usually drops to around -5 °C (23.5 °F). However, it dropped to -7.3 °C (18.9 °F) in January 2001.
On the warmest days of the month, the temperature usually reaches around 12 °C (53 °F). However, it reached 15.6 °C (60.1 °F) in January 1997.
Precipitation amounts to 40 mm (1.6 in), distributed over 8 days.
The day lasts on average 9 hours and 55 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 48% of the time.
The average humidity is 66%.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 11.5 °C (53 °F). Therefore, the sea is very cold for swimming.

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In February, the weather in Sendai is usually cold. The average temperature is of 2.7 °C (37 °F), with a minimum of -1.1 °C (30 °F) and a maximum of 6.5 °C (43.7 °F).
On the coldest nights of the month, the temperature usually drops to around -5 °C (23.5 °F). However, it dropped to -7.5 °C (18.5 °F) in February 2006.
On the warmest days of the month, the temperature usually reaches around 14 °C (57 °F). However, it reached 20.9 °C (69.6 °F) in February 2016.
Precipitation amounts to 35 mm (1.4 in), distributed over 7 days.
The day lasts on average 10 hours and 50 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 51% of the time.
The average humidity is 64%.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 10 °C (49.5 °F). Therefore, the sea is very cold for swimming.

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In March, the weather in Sendai is usually quite cold. The average temperature is of 5.7 °C (42 °F), with a minimum of 1.4 °C (34.5 °F) and a maximum of 10 °C (50 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -2.5 °C (27 °F). However, it dropped to -4.6 °C (23.7 °F) in March 2005.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 18 °C (65 °F). However, it reached 24.2 °C (75.6 °F) in March 2009.
Precipitation amounts to 75 mm (3 in), distributed over 9 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 48% of the time.
The average humidity is 61%.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 9.5 °C (49.5 °F). Therefore, the sea is very cold for swimming.

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In April, the weather in Sendai is usually mild. The average temperature is of 10.9 °C (52 °F), with a minimum of 6.3 °C (43.3 °F) and a maximum of 15.5 °C (59.9 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 1 °C (34 °F). However, it dropped to -1.2 °C (29.8 °F) in April 1991.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 24 °C (75 °F). However, it reached 29.9 °C (85.8 °F) in April 2018.
Precipitation amounts to 90 mm (3.5 in), distributed over 9 days.
The day lasts on average 13 hours and 10 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 63%.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 11.5 °C (52.5 °F). Therefore, the sea is very cold for swimming.

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In May, the weather in Sendai is usually very mild. The average temperature is of 16.0 °C (61 °F), with a minimum of 11.7 °C (53.1 °F) and a maximum of 20.2 °C (68.4 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 6.5 °C (43.5 °F). However, it dropped to 1.8 °C (35.2 °F) in May 1992.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 27.5 °C (81.5 °F). However, it reached 32.1 °C (89.8 °F) in May 2019.
Precipitation amounts to 110 mm (4.3 in), distributed over 10 days.
The day lasts on average 14 hours and 20 minutes. So the days are long.
There are on average 6 hours of sunshine per day. So, the sun shines 43% of the time.
The average humidity is 70%.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 14.5 °C (58 °F). Therefore, the sea is very cold for swimming.

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In June, the weather in Sendai is usually warm. The average temperature is of 19.6 °C (67 °F), with a minimum of 16.1 °C (61 °F) and a maximum of 23.1 °C (73.6 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 11.5 °C (53 °F). However, it dropped to 8.6 °C (47.5 °F) in June 2010.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 29.5 °C (85.5 °F). However, it reached 34.4 °C (93.9 °F) in June 2011.
Precipitation amounts to 145 mm (5.7 in), distributed over 12 days.
The day lasts on average 14 hours and 50 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 5 hours of sunshine per day. So, the sun shines 32% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 9 kph (6 mph).
The average sea temperature is of 18.5 °C (65.5 °F). Therefore, the sea is very cool for swimming.

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In July, the weather in Sendai is usually warm to hot and muggy. The average temperature is of 23.4 °C (74 °F), with a minimum of 20.2 °C (68.4 °F) and a maximum of 26.6 °C (79.9 °F).
On the coldest nights of the month, the temperature usually drops to around 16.5 °C (61.5 °F). However, it dropped to 12.6 °C (54.7 °F) in July 1993.
On the warmest days of the month, the temperature usually reaches around 33 °C (92 °F). However, it reached 36.7 °C (98.1 °F) in July 2018.
Precipitation amounts to 180 mm (7.1 in), distributed over 16 days.
The day lasts on average 14 hours and 30 minutes. So the days are long.
There are on average 4 hours of sunshine per day. So, the sun shines 28% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 8 kph (5 mph).
The average sea temperature is of 21.5 °C (71 °F). Therefore, the sea is cool for swimming.

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In August, the warmest month of the year, the weather in Sendai is usually warm to hot and muggy. The average temperature is of 24.9 °C (77 °F), with a minimum of 21.6 °C (70.9 °F) and a maximum of 28.2 °C (82.8 °F).
On the coldest nights of the month, the temperature usually drops to around 17.5 °C (63.5 °F). However, it dropped to 14.6 °C (58.3 °F) in August 1991.
On the warmest days of the month, the temperature usually reaches around 34 °C (93.5 °F). However, it reached 37.3 °C (99.1 °F) in August 2018.
Precipitation amounts to 160 mm (6.3 in), distributed over 13 days.
The day lasts on average 13 hours and 35 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 34% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is 9 kph (6 mph).
The average sea temperature is of 24.5 °C (76 °F). Therefore, the sea is warm enough for swimming.

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In September, the weather in Sendai is usually warm. The average temperature is of 21.5 °C (71 °F), with a minimum of 18 °C (64.4 °F) and a maximum of 25 °C (77 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 12.5 °C (54.5 °F). However, it dropped to 8.2 °C (46.8 °F) in September 2001.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 31.5 °C (88.5 °F). However, it reached 35.5 °C (95.9 °F) in September 2010.
Precipitation amounts to 195 mm (7.7 in), distributed over 13 days.
The day lasts on average 12 hours and 25 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 34% of the time.
The average humidity is 78%. Hence, the air is normally humid.
The average wind speed is 8 kph (5 mph).
The average sea temperature is of 23.5 °C (74 °F). Therefore, the sea can be considered barely acceptable for swimming.

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In October, the weather in Sendai is usually very mild. The average temperature is of 15.8 °C (61 °F), with a minimum of 11.9 °C (53.4 °F) and a maximum of 19.8 °C (67.6 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 6 °C (42.5 °F). However, it dropped to 2.7 °C (36.9 °F) in October 2004.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 26.5 °C (79.5 °F). However, it reached 29.9 °C (85.8 °F) in October 1998.
Precipitation amounts to 150 mm (5.9 in), distributed over 10 days.
The day lasts on average 11 hours and 10 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 42% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is 9 kph (6 mph).
The average sea temperature is of 20.5 °C (68.5 °F). Therefore, the sea is cool for swimming.

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In November, the weather in Sendai is usually mild. The average temperature is of 9.8 °C (50 °F), with a minimum of 5.6 °C (42.1 °F) and a maximum of 14.1 °C (57.4 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 0.5 °C (33 °F). However, it dropped to -1.6 °C (29.1 °F) in November 2016.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 20.5 °C (69 °F). However, it reached 24 °C (75.2 °F) in November 2009.
Precipitation amounts to 60 mm (2.4 in), distributed over 7 days.
The day lasts on average 10 hours and 5 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 47% of the time.
The average humidity is 68%.
The average wind speed is 9 kph (6 mph).
The average sea temperature is of 17.5 °C (63.5 °F). Therefore, the sea is cold for swimming.

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In December, the weather in Sendai is usually quite cold. The average temperature is of 4.6 °C (40 °F), with a minimum of 0.9 °C (33.6 °F) and a maximum of 8.3 °C (46.9 °F).
On the coldest nights of the month, the temperature usually drops to around -3 °C (26.5 °F). However, it dropped to -5.4 °C (22.3 °F) in December 2020.
On the warmest days of the month, the temperature usually reaches around 15.5 °C (59.5 °F). However, it reached 21.6 °C (70.9 °F) in December 2004.
Precipitation amounts to 45 mm (1.8 in), distributed over 8 days.
The day lasts on average 9 hours and 35 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 4.5 hours of sunshine per day. So, the sun shines 46% of the time.
The average humidity is 68%.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 14.5 °C (58 °F). Therefore, the sea is very cold for swimming.