Iwata climate
Iwata (Japan) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 18 °C65 °F, and about 2,086 mm82 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Iwata climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 1152 | 745 | 949 | 793.1 |
| Feb | 1253 | 846 | 1050 | 1024.0 |
| Mar | 1458 | 1050 | 1254 | 1546.1 |
| Apr | 1864 | 1457 | 1660 | 1877.3 |
| May | 2170 | 1864 | 1967 | 2017.9 |
| Jun | 2474 | 2170 | 2272 | 2489.8 |
| Jul | 2780 | 2576 | 2678 | 25610 |
| Aug | 2883 | 2679 | 2781 | 1706.7 |
| Sep | 2680 | 2475 | 2577 | 2419.5 |
| Oct | 2373 | 2068 | 2170 | 2469.7 |
| Nov | 1865 | 1560 | 1762 | 1184.6 |
| Dec | 1457 | 1050 | 1253 | 833.3 |
| Year | 2883 | 745 | 1865 | 2,08682 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 71% | 59% | 2.7 | 10:04 |
| Feb | 70% | 61% | 3.3 | 10:53 |
| Mar | 71% | 59% | 4.3 | 11:52 |
| Apr | 74% | 62% | 5.0 | 13:01 |
| May | 79% | 66% | 5.3 | 13:58 |
| Jun | 85% | 78% | 4.8 | 14:28 |
| Jul | 88% | 69% | 5.3 | 14:16 |
| Aug | 85% | 55% | 5.6 | 13:27 |
| Sep | 80% | 62% | 4.3 | 12:20 |
| Oct | 75% | 62% | 3.3 | 11:14 |
| Nov | 71% | 58% | 2.7 | 10:18 |
| Dec | 71% | 57% | 2.4 | 9:50 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Iwata is like
The warmest month is August, with an average high of 28 °C83 °F and a low of 26 °C79 °F. The coldest is January, when highs average 11 °C52 °F and lows 7 °C45 °F. There is a clear seasonal cycle, with 17.9 °C32.3 °F between the average temperature of the warmest and the coolest month.
It is very wet, receiving about 2,086 mm82 in of precipitation per year. The wettest three-month stretch is May–July, which brings 34% of the annual total. The wettest month is July (256 mm10 in), the driest is January (79 mm3.1 in).
Relative humidity ranges from 70% in February to 88% in July. The clearest skies (lowest average cloud amount, 55%) are typical of August. Average wind speed near the ground ranges from 15 km/h (10 mph) in August to 26 km/h (16 mph) in January. Daylight lasts from about 9.8 hours in December to 14.5 hours in June.
Best time to visit Iwata
Based on these averages, the most comfortable months for sightseeing and outdoor activities are November: average highs of 18 °C65 °F to 18 °C65 °F with 118 mm4.6 in to 118 mm4.6 in of precipitation per month.
The most challenging month is July, which is very wet (256 mm10 in) and humid (88% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Iwata
- Winter (December–February) — highs 1152 to 14 °C57 °F, lows 745 to 10 °C50 °F, about 88 mm3.5 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
- Spring (March–May) — highs 1458 to 21 °C70 °F, lows 1050 to 18 °C64 °F, about 181 mm7.1 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an umbrella or light rain jacket.
- Summer (June–August) — highs 2474 to 28 °C83 °F, lows 2170 to 26 °C79 °F, about 225 mm8.9 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and a good rain jacket or umbrella and quick-drying shoes.
- Autumn (September–November) — highs 1865 to 26 °C80 °F, lows 1560 to 24 °C75 °F, about 202 mm7.9 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and a good rain jacket or umbrella and quick-drying shoes.
How Iwata compares
Compared with Hamamatsu, about 11 km to the west, Iwata has practically the same average temperature and receives 6% more precipitation (2,086 mm82 in vs 1,970 mm78 in).
Of the 111 places in Japan covered by World Climates, Iwata is the 6th warmest by annual mean temperature and the 12th wettest by annual precipitation. See all of them on the Japan climate page.
Places in other countries with the most similar temperature and rainfall pattern: Zhoushan (China, Cfa), Taizhou (China, Cfa) and Wilmington (United States, Cfa).
Nearby places
- Hamamatsu 11 km · 18 °C64 °F · 1,970 mm78 in
- Toyohashi 43 km · 16 °C61 °F · 1,776 mm70 in
- Shizuoka 58 km · 16 °C61 °F · 1,875 mm74 in
- Okazaki 68 km · 16 °C60 °F · 1,741 mm69 in
- Toyota 77 km · 16 °C60 °F · 1,741 mm69 in
- Iida 91 km · 13 °C56 °F · 1,586 mm62 in
- Fuji 92 km · 17 °C63 °F · 1,887 mm74 in
- Tajimi 95 km · 14 °C58 °F · 1,803 mm71 in
Frequently asked questions
What is the warmest month in Iwata?
August is the warmest month in Iwata, with an average high of 28 °C (83 °F) and an average low of 26 °C (79 °F).
What is the coldest month in Iwata?
January is the coldest month, with an average high of 11 °C (52 °F) and an average low of 7 °C (45 °F).
When does it rain the most in Iwata?
July is the wettest month with about 256 mm (10.1 in) of precipitation; January is the driest with about 79 mm (3.1 in).
What is the best time to visit Iwata?
Judging by long-term averages, the most comfortable months are November.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.