Nagaoka climate
Nagaoka (Japan) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 14 °C57 °F, and about 1,922 mm76 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Nagaoka climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 540 | 134 | 337 | 2058.1 | 13 |
| Feb | 542 | 133 | 338 | 1224.8 | 15 |
| Mar | 948 | 337 | 642 | 1224.8 | 6 |
| Apr | 1559 | 744 | 1152 | 1014.0 | 0 |
| May | 2169 | 1254 | 1762 | 923.6 | 0 |
| Jun | 2576 | 1763 | 2170 | 1295.1 | 0 |
| Jul | 2882 | 2271 | 2577 | 2198.6 | 0 |
| Aug | 3085 | 2373 | 2679 | 1596.3 | 0 |
| Sep | 2679 | 1966 | 2272 | 1716.7 | 0 |
| Oct | 2068 | 1356 | 1762 | 1686.6 | 0 |
| Nov | 1457 | 847 | 1152 | 1877.4 | 0 |
| Dec | 846 | 438 | 642 | 2489.8 | 2 |
| Year | 3085 | 133 | 1457 | 1,92276 | 36 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 86% | 91% | 1.5 | 9:51 |
| Feb | 82% | 86% | 2.3 | 10:45 |
| Mar | 79% | 79% | 3.5 | 11:51 |
| Apr | 77% | 70% | 4.5 | 13:07 |
| May | 77% | 68% | 5.3 | 14:10 |
| Jun | 80% | 76% | 5.1 | 14:44 |
| Jul | 83% | 79% | 4.7 | 14:30 |
| Aug | 80% | 70% | 4.9 | 13:35 |
| Sep | 80% | 74% | 3.9 | 12:22 |
| Oct | 80% | 71% | 2.9 | 11:09 |
| Nov | 82% | 77% | 1.9 | 10:06 |
| Dec | 86% | 87% | 1.4 | 9:35 |
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 Nagaoka is like
The warmest month is August, with an average high of 30 °C85 °F and a low of 23 °C73 °F. The coldest is January, when highs average 5 °C40 °F and lows 1 °C34 °F. Seasons are strongly marked: the warmest month is on average 23.4 °C42.2 °F warmer than the coldest.
It is wet, with about 1,922 mm76 in of precipitation per year. The wettest three-month stretch is November–January, which brings 33% of the annual total. The wettest month is December (248 mm9.8 in), the driest is May (92 mm3.6 in).
Relative humidity ranges from 77% in April to 86% in December. The clearest skies (lowest average cloud amount, 68%) are typical of May. Average wind speed near the ground ranges from 4 km/h (2 mph) in July to 12 km/h (7 mph) in February. Daylight lasts from about 9.6 hours in December to 14.7 hours in June.
A lasting snow cover is typical in December–March, when the average snow depth in the reanalysis exceeds 10 cm (deepest in January, about 16 cm).
Best time to visit Nagaoka
Based on these averages, the most comfortable months for sightseeing and outdoor activities are May: average highs of 21 °C69 °F to 21 °C69 °F with 92 mm3.6 in to 92 mm3.6 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of 5 °C40 °F and very wet (205 mm8.1 in).
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 Nagaoka
- Winter (December–February) — highs 540 to 8 °C46 °F, lows 133 to 4 °C38 °F, about 191 mm7.5 in of precipitation a month. Pack a warm coat, layers and closed shoes and an umbrella or light rain jacket.
- Spring (March–May) — highs 948 to 21 °C69 °F, lows 337 to 12 °C54 °F, about 105 mm4.1 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 2576 to 30 °C85 °F, lows 1763 to 23 °C73 °F, about 169 mm6.7 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an umbrella or light rain jacket.
- Autumn (September–November) — highs 1457 to 26 °C79 °F, lows 847 to 19 °C66 °F, about 175 mm6.9 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.
How Nagaoka compares
Compared with Niigata, about 55 km to the north, Nagaoka is on average 0.6 °C1.2 °F cooler and receives 13% more precipitation (1,922 mm76 in vs 1,702 mm67 in). The difference is largest in December (2.1 °C3.8 °F cooler).
Of the 111 places in Japan covered by World Climates, Nagaoka is the 81st warmest by annual mean temperature and the 24th 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: Atlantic City (United States, Cfa), New York City (United States, Cfa) and Brooklyn (United States, Cfa).
Nearby places
- Niigata 55 km · 15 °C58 °F · 1,702 mm67 in
- Jōetsu 64 km · 15 °C58 °F · 1,812 mm71 in
- Aizu-Wakamatsu 97 km · 12 °C54 °F · 1,349 mm53 in
- Nagano 107 km · 12 °C54 °F · 1,462 mm58 in
- Maebashi 119 km · 14 °C57 °F · 1,469 mm58 in
- Nasushiobara 120 km · 12 °C54 °F · 1,405 mm55 in
- Takasaki 125 km · 14 °C58 °F · 1,434 mm56 in
- Utsunomiya 134 km · 13 °C56 °F · 1,474 mm58 in
Frequently asked questions
What is the warmest month in Nagaoka?
August is the warmest month in Nagaoka, with an average high of 30 °C (85 °F) and an average low of 23 °C (73 °F).
What is the coldest month in Nagaoka?
January is the coldest month, with an average high of 5 °C (40 °F) and an average low of 1 °C (34 °F).
When does it rain the most in Nagaoka?
December is the wettest month with about 248 mm (9.8 in) of precipitation; May is the driest with about 92 mm (3.6 in).
What is the best time to visit Nagaoka?
Judging by long-term averages, the most comfortable months are May.
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.
The grid cell’s average elevation is 126 m, while Nagaoka lies at about 23 m. Temperatures on this page were therefore adjusted by +0.7 °C1.2 °F using the standard lapse rate of 6.5 °C per 1,000 m.