The climate of Okayama, a Japanese city in the southern part of Honshu Island, in the region called Chugoku, is
, with quite mild winters and hot, moist, and rainy summers. Like the rest of Japan, the city is affected by the
: in winter, the northwest cold currents prevail, while in summer, they are replaced by hot and humid currents of tropical origin.
Okayama is located on the coast, in the Seto Inland Sea, an area relatively protected both from the winter monsoon (since we are on the south side) and from the summer monsoon as well as typhoons. In fact, on the other side of the sea, we find the island of Shikoku, which protects it from the south winds with its mountains.
, there are fairly mild periods, with highs above 12 °C (54 °F), alternating with cold periods, with wind, rain, and highs around 5/7 °C (41/45 °F) or less. Night frosts are typically light, both because of the influence of the sea and because of the heat island effect. However, in January 1963, the temperature dropped to -8.9 °C (16 °F). Snowfall is very rare, even more so than in Tokyo.
are hot and humid; there can be periods of good weather, with maximum temperatures around 35 °C (95 °F) or above and high humidity, but also periods of bad weather due to the summer monsoon. August is the hottest month, both because of the thermal inertia of the sea and because of the lower frequency of periods of bad weather.
is quite abundant (although this is one of the driest areas of Japan), in fact it amounts to 1,100 millimeters (43 inches) per year. Winter is undoubtedly the driest season. The rainiest months are June and July, ie the first period of the rainy season (called
). In August, there is a certain decrease in rain frequency: on average, among the summer months, it is the hottest as well as the driest and sunniest.
, the Japanese garden, considered as one of the three most important, together with the Kenroku-en in
.
in Okayama, quite good in winter, never becomes very good, but in summer, it is higher than in other parts of Japan. The sunniest months are April, May and August, with around 6 hours and a half of sunshine per day, and there are more than 2,000 hours of sunshine per year. This area is known to the Japanese as "The Sunny Country", but above all because the rains are relatively scarcer.
in Okayama is warm enough for swimming, with a temperature of 23 °C (73 °F) or more, from July to October, and it becomes pleasantly warm in August.
From June to October (but especially from August to early October), Okayama may be affected by
, the tropical cyclones of Southeast Asia, though, as mentioned, this area of the Seto Inland Sea is relatively sheltered.
As regards to the climate, the best times to visit Okayama are spring and autumn, and in particular, from mid-April to mid-May and from late October to mid-November.
in Okayama reaches its peak around April the 3rd. About a week passes between the beginning and the peak of the flowering. The blooming date can vary by a few days, or even a week, earlier or later, depending on the year. Even though in some years it can get a little cold, with highs around 12 °C (54 °F), you can also take advantage of this period.
In summer, August is partly preferable to July, having more sunshine and less rainfall, but it is also true that it is hotter and there's a greater risk of typhoons.
The following meteorological data were recorded at the city station. The temperatures of the airport, located north of the city, in a green area, and at 240 meters (800 feet) of altitude, are a bit lower.
. Here are the average temperatures.
January, the coldest month of the year, is generally a quite cold month. The average temperature is of
5.2 °C, with a minimum of
1.2 °C and a maximum of
9.3 °C.
On the coldest nights of the month, the temperature usually drops to around
-2.5 °C. However, it dropped to
-5.5 °C in January 2018.
On the warmest days of the month, the temperature usually reaches around
14 °C. However, it reached
16.9 °C in January 2016.
Precipitation amounts to
35 mm, distributed over 5 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 48% of the time.
The average humidity is 69%.
The average wind speed is of
10 kph.
The average sea temperature is of
16.2 °C. Therefore, the sea is cold for swimming.
February is generally a quite cold month. The average temperature is of
6 °C, with a minimum of
1.6 °C and a maximum of
10.3 °C.
On the coldest nights of the month, the temperature usually drops to around
-2.5 °C. However, it dropped to
-6.1 °C in February 2018.
On the warmest days of the month, the temperature usually reaches around
16.5 °C. However, it reached
22.1 °C in February 2010.
Precipitation amounts to
45 mm, distributed over 7 days.
The day lasts on average 11 hours and 0 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 47% of the time.
The average humidity is 66%.
The average wind speed is of
9 kph.
The average sea temperature is of
15 °C. Therefore, the sea is cold for swimming.
March is generally a mild month. The average temperature is of
9.2 °C, with a minimum of
4.4 °C and a maximum of
13.9 °C.
On the coldest nights of the month, the temperature usually drops to around
-0.5 °C. However, it dropped to
-3.2 °C in March 2015.
On the warmest days of the month, the temperature usually reaches around
21 °C. However, it reached
24.8 °C in March 2018.
Precipitation amounts to
85 mm, distributed over 9 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 48% of the time.
The average humidity is 65%.
The average wind speed is of
8 kph.
The average sea temperature is of
14.9 °C. Therefore, the sea is cold for swimming.
April is generally a very mild month. The average temperature is of
14.6 °C, with a minimum of
9.5 °C and a maximum of
19.8 °C.
On the coldest nights of the month, the temperature usually drops to around
2.5 °C. However, it dropped to
0.3 °C in April 1996.
On the warmest days of the month, the temperature usually reaches around
26.5 °C. However, it reached
29.6 °C in April 2004.
Precipitation amounts to
90 mm, distributed over 10 days.
The day lasts on average 13 hours and 5 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 60%.
The average wind speed is of
8 kph.
The average sea temperature is of
16.1 °C. Therefore, the sea is cold for swimming.
May is generally a warm month. The average temperature is of
19.8 °C, with a minimum of
14.7 °C and a maximum of
24.9 °C.
On the coldest nights of the month, the temperature usually drops to around
9 °C. However, it dropped to
5.7 °C in May 1991.
On the warmest days of the month, the temperature usually reaches around
30.5 °C. However, it reached
33.6 °C in May 2015.
Precipitation amounts to
115 mm, distributed over 9 days.
The day lasts on average 14 hours and 0 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 47% of the time.
The average humidity is 64%.
The average wind speed is of
8 kph.
The average sea temperature is of
18.6 °C. Therefore, the sea is very cool for swimming.
June is generally a warm to hot, muggy month. The average temperature is of
23.6 °C, with a minimum of
19.5 °C and a maximum of
27.8 °C.
On the coldest nights of the month, the temperature usually drops to around
15 °C. However, it dropped to
11.9 °C in June 2016.
On the warmest days of the month, the temperature usually reaches around
33.5 °C. However, it reached
37 °C in June 2013.
Precipitation amounts to
170 mm, distributed over 12 days.
The day lasts on average 14 hours and 25 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 35% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is of
7 kph.
The average sea temperature is of
21.8 °C. Therefore, the sea is cool for swimming.
July is generally a very hot, muggy month. The average temperature is of
27.8 °C, with a minimum of
23.9 °C and a maximum of
31.7 °C.
On the coldest nights of the month, the temperature usually drops to around
20.5 °C. However, it dropped to
17.3 °C in July 1992.
On the warmest days of the month, the temperature usually reaches around
36 °C. However, it reached
38.1 °C in July 2018.
Precipitation amounts to
175 mm, distributed over 11 days.
The day lasts on average 14 hours and 10 minutes. So the days are long.
There are on average 5.5 hours of sunshine per day. So, the sun shines 39% of the time.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is of
7 kph.
The average sea temperature is of
25.1 °C. Therefore, the sea is warm enough for swimming.
August, the hottest month of the year, is generally a very hot month. The average temperature is of
29 °C, with a minimum of
24.9 °C and a maximum of
33 °C.
On the coldest nights of the month, the temperature usually drops to around
21 °C. However, it dropped to
17.3 °C in August 2018.
On the warmest days of the month, the temperature usually reaches around
36.5 °C. However, it reached
39.3 °C in August 1994.
Precipitation amounts to
95 mm, distributed over 8 days.
The day lasts on average 13 hours and 25 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 69%.
The average wind speed is of
8 kph.
The average sea temperature is of
27.3 °C. Therefore, the sea is pleasantly warm and allows long swims.
September is generally a warm to hot, muggy month. The average temperature is of
24.8 °C, with a minimum of
20.8 °C and a maximum of
28.7 °C.
On the coldest nights of the month, the temperature usually drops to around
15 °C. However, it dropped to
11.5 °C in September 1992.
On the warmest days of the month, the temperature usually reaches around
33.5 °C. However, it reached
37.1 °C in September 2020.
Precipitation amounts to
140 mm, distributed over 10 days.
The day lasts on average 12 hours and 25 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 42% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is of
7 kph.
The average sea temperature is of
26 °C. Therefore, the sea is warm enough for swimming.
October is generally a warm month. The average temperature is of
18.7 °C, with a minimum of
14.4 °C and a maximum of
23 °C.
On the coldest nights of the month, the temperature usually drops to around
8 °C. However, it dropped to
2.5 °C in October 2020.
On the warmest days of the month, the temperature usually reaches around
28.5 °C. However, it reached
33.4 °C in October 2018.
Precipitation amounts to
95 mm, distributed over 8 days.
The day lasts on average 11 hours and 20 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is of
7 kph.
The average sea temperature is of
23.4 °C. Therefore, the sea can be considered barely acceptable for swimming.
November is generally a mild month. The average temperature is of
12.7 °C, with a minimum of
8.3 °C and a maximum of
17.1 °C.
On the coldest nights of the month, the temperature usually drops to around
2.5 °C. However, it dropped to
0.3 °C in November 2013.
On the warmest days of the month, the temperature usually reaches around
22.5 °C. However, it reached
24.6 °C in November 2020.
Precipitation amounts to
55 mm, distributed over 6 days.
The day lasts on average 10 hours and 20 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 50% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is of
8 kph.
The average sea temperature is of
21 °C. Therefore, the sea is cool for swimming.
December is generally a quite mild month. The average temperature is of
7.4 °C, with a minimum of
3.3 °C and a maximum of
11.6 °C.
On the coldest nights of the month, the temperature usually drops to around
-1 °C. However, it dropped to
-2.7 °C in December 2013.
On the warmest days of the month, the temperature usually reaches around
16.5 °C. However, it reached
20.6 °C in December 2018.
Precipitation amounts to
40 mm, distributed over 6 days.
The day lasts on average 9 hours and 55 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 5 hours of sunshine per day. So, the sun shines 50% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is of
9 kph.
The average sea temperature is of
18.4 °C. Therefore, the sea is very cool for swimming.