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Iida, Nagano Weather by Month and Climate Averages
Monthly normals · Rain · Snow
Sunshine · Freeze dates · Records · Best time to visit
What is the weather like in Iida, Nagano?
Iida, Nagano gets 1516 mm of precipitation a year over about 107 rainy days. August is the warmest month (average high 32°C) and January the coldest (average low -4°C).
Humid subtropical climate
Iida, Nagano has hot summers and chilly winters. Daytime highs range from about 7°C in January to 32°C in August. July is usually the wettest month. The most comfortable time to visit is typically April to June and October, when daytime highs sit near 23°C.
| Season | Months | Avg low | Avg high |
|---|---|---|---|
| Winter | Dec–Feb | -3° | 8° |
| Spring | Mar–May | 5° | 18° |
| Summer | Jun–Aug | 19° | 29° |
| Autumn | Sep–Nov | 10° | 21° |
How much rain does Iida get?
Iida gets 1516 mm of precipitation in an average year, spread over about 107 days with measurable rain. That is fewer rainy days than 58% of Japan.
July is the wettest month, with 217 mm. December is the driest, with 57 mm. July has the most rainy days, about 12.
The longest dry spell in the last five years lasted 19 days, to January 12, 2023.
From October 2025 to September 2026 Iida got 3830 mm of rain, against a normal of 1516 mm for those months. September 2026 had the most, with 2407 mm.
Iida weather by month
Iida weather in January
In January, Iida averages a high of 7°C and a low of -4°C. It gets 57 mm of precipitation over about 7 rainy days. Estimated sunshine is 48% of daylight hours, derived from ERA5 cloud cover. The January record high is 17°C (1973) and the record low is -13°C (1970).
Iida weather in February
In February, Iida averages a high of 9°C and a low of -4°C. It gets 71 mm of precipitation over about 7 rainy days. Estimated sunshine is 47% of daylight hours, derived from ERA5 cloud cover. The February record high is 21°C (2024) and the record low is -13°C (1984).
Iida weather in March
In March, Iida averages a high of 13°C and a low of -1°C. It gets 120 mm of precipitation over about 9 rainy days. Estimated sunshine is 44% of daylight hours, derived from ERA5 cloud cover. The March record high is 26°C (2021) and the record low is -9°C (1971).
Iida weather in April
In April, Iida averages a high of 19°C and a low of 5°C. It gets 128 mm of precipitation over about 9 rainy days. Estimated sunshine is 38% of daylight hours, derived from ERA5 cloud cover. The April record high is 31°C (2003) and the record low is -4°C (2001). April is one of the most comfortable months to visit.
Iida weather in May
In May, Iida averages a high of 24°C and a low of 11°C. It gets 138 mm of precipitation over about 9 rainy days. Estimated sunshine is 30% of daylight hours, derived from ERA5 cloud cover. The May record high is 34°C (2017) and the record low is 0°C (1972). May is one of the most comfortable months to visit.
Iida weather in June
In June, Iida averages a high of 27°C and a low of 16°C. It gets 180 mm of precipitation over about 12 rainy days. Estimated sunshine is 19% of daylight hours, derived from ERA5 cloud cover. The June record high is 37°C (2022) and the record low is 7°C (1978). June is one of the most comfortable months to visit.
Iida weather in July
In July, Iida averages a high of 30°C and a low of 20°C. It gets 217 mm of precipitation over about 12 rainy days. Estimated sunshine is 20% of daylight hours, derived from ERA5 cloud cover. The July record high is 37°C (2022) and the record low is 12°C (1976).
Iida weather in August
In August, Iida averages a high of 32°C and a low of 21°C. It gets 132 mm of precipitation over about 10 rainy days. Estimated sunshine is 28% of daylight hours, derived from ERA5 cloud cover. The August record high is 38°C (2018) and the record low is 13°C (1981).
Iida weather in September
In September, Iida averages a high of 27°C and a low of 17°C. It gets 190 mm of precipitation over about 10 rainy days. Estimated sunshine is 26% of daylight hours, derived from ERA5 cloud cover. The September record high is 36°C (2010) and the record low is 6°C (1992).
Iida weather in October
In October, Iida averages a high of 21°C and a low of 10°C. It gets 147 mm of precipitation over about 8 rainy days. Estimated sunshine is 43% of daylight hours, derived from ERA5 cloud cover. The October record high is 31°C (2013) and the record low is -1°C (1984). October is one of the most comfortable months to visit.
Iida weather in November
In November, Iida averages a high of 15°C and a low of 3°C. It gets 80 mm of precipitation over about 7 rainy days. Estimated sunshine is 52% of daylight hours, derived from ERA5 cloud cover. The November record high is 24°C (2000) and the record low is -6°C (1973).
Iida weather in December
In December, Iida averages a high of 9°C and a low of -2°C. It gets 57 mm of precipitation over about 8 rainy days. Estimated sunshine is 49% of daylight hours, derived from ERA5 cloud cover. The December record high is 19°C (1987) and the record low is -12°C (1973).
Sunshine, humidity and wind in Iida
November is the sunniest month in Iida, with estimated sunshine of 52% of daylight hours from ERA5 cloud cover. June is the cloudiest, at 19%. The annual cloud-cover estimate is 37% of daylight hours; it is not a measurement of sunshine duration. Iida is cloudier than 61% of Japan.
Humidity peaks in July at 81% and is lowest in February at 61%.
Iida has about 24 days a year above 32°C. Iida is hotter than 64% of Japan.
First and last freeze in Iida
The first fall freeze in Iida typically comes around November 14, and the last spring freeze around April 6. That leaves a frost-free growing season of about 222 days.
Iida weather records
These records cover IIDA during 1970–2026. Earlier records or other stations in the city may differ.
The hottest temperature on record at the Iida station is 38°C, on August 6, 2018. The coldest is -13°C, on February 4, 1984.
The wettest day in the available station history brought 503 mm of precipitation, on September 28, 2026.
42 all-time records have been set at the station since 1970.
The best time to visit Iida
The most comfortable time to visit is typically April to June and October, when daytime highs sit near 23°C.
Winter (December–February) is chilly, with average highs around 8°C and lows near -3°C.
Spring (March–May) is mild, with average highs around 19°C and lows near 5°C.
Summer (June–August) is hot, with average highs around 29°C and lows near 19°C. It can feel humid.
Autumn (September–November) is warm, with average highs around 21°C and lows near 10°C.
Monthly climate
| Month | Average low | Average high | Precip | Rain days | Humidity | Estimated sunshine | Record high | Record low |
|---|---|---|---|---|---|---|---|---|
| January | -4° | 7° | 57 mm | 7 | 64% | 48% | 17° | -13° |
| February | -4° | 9° | 71 mm | 7 | 61% | 47% | 21° | -13° |
| March | -1° | 13° | 120 mm | 9 | 62% | 44% | 26° | -9° |
| April | 5° | 19° | 128 mm | 9 | 62% | 38% | 31° | -4° |
| May | 11° | 24° | 138 mm | 9 | 68% | 30% | 34° | 0° |
| June | 16° | 27° | 180 mm | 12 | 76% | 19% | 37° | 7° |
| July | 20° | 30° | 217 mm | 12 | 81% | 20% | 37° | 12° |
| August | 21° | 32° | 132 mm | 10 | 79% | 28% | 38° | 13° |
| September | 17° | 27° | 190 mm | 10 | 80% | 26% | 36° | 6° |
| October | 10° | 21° | 147 mm | 8 | 74% | 43% | 31° | -1° |
| November | 3° | 15° | 80 mm | 7 | 72% | 52% | 24° | -6° |
| December | -2° | 9° | 57 mm | 8 | 69% | 49% | 19° | -12° |
Station: IIDA, 0 km from the city. Temperature normal baseline: 1991–2020, calculated from available NOAA GHCN-Daily observations. Available station history: 1970–2026; record values refer to this station and period, not the entire city’s history. Precipitation includes rain and the water equivalent of frozen precipitation; snowfall depth is shown separately when available. Sources and methods
From ERA5 reanalysis. Sunshine is estimated from cloud cover.
Iida climate questions
How much rain does Iida get?
Iida gets 1516 mm of precipitation in an average year, over about 107 rainy days.
What is the wettest month in Iida?
July is the wettest month in Iida, with 217 mm. December is the driest, with 57 mm.
How many rainy days does Iida have a year?
Iida has about 107 days with measurable rain in an average year. July has the most, about 12.
What is the hottest month in Iida?
August is the warmest month in Iida, with an average high of 32°C.
What is the coldest month in Iida?
January is the coldest month in Iida, with an average low of -4°C.
What is the record high temperature in Iida?
Within the available 1970–2026 station history, the record high at the Iida station is 38°C, set on August 6, 2018. The record low is -13°C, on February 4, 1984.
What is the sunniest month in Iida?
November is the sunniest month in Iida, with estimated sunshine of 52% of daylight hours from ERA5 cloud cover. June is the cloudiest.
When is the first frost in Iida?
The first fall freeze in Iida typically comes around November 14. The last spring freeze is around April 6.
What is the best time to visit Iida?
The most comfortable time to visit is typically April to June and October, when daytime highs sit near 23°C.