Yamagata weather by month

At a glance

Quietest month in Yamagata: April. Busiest: August, with about 1.7 times as many guest nights as April. In Yamagata, August is warmest (average high 30.5 °C) and July wettest (187 mm of rain).

  1. January: 7.4%, quieter than average
  2. February: 7.1%, quieter than average
  3. March: 7.8%, quieter than average
  4. April: 6.8%, quieter than average
  5. May: 8.6%, busier than average
  6. June: 8.3%, quieter than average
  7. July: 8.8%, busier than average
  8. August: 11.3%, one of the two busiest months
  9. September: 8.5%, busier than average
  10. October: 9.8%, one of the two busiest months
  11. November: 8.4%, busier than average
  12. December: 7.3%, quieter than average

quieter than average busier than average two busiest months · each month's share of Yamagata's 2025 guest nights; an even spread is 8.3% a month

Weather
Coldest: January and February (average low −3.1 °C). Driest: February (63 mm). Month by month
Holidays
18 national public holidays in 2026. See the dates
Next
Plan a trip with your dates
TL;DR

At the Yamagata (山形) weather station, which we use for Yamagata, the warmest month is August (average high 30.5 °C) and the coldest January and February (average low −3.1 °C), averaged over 1991–2020. The wettest month is July (187 mm of rain). Yamagata's quietest month for visitors in 2025 was April.

A historic stone building with a clock tower in Yamagata City, Japan
A historic stone building with a clock tower in Yamagata City, Japan. Photo by なかむーちょ Nakamuhcho on Pexels.

Yamagata weather by month

Averages for 1991–2020 at the Yamagata (山形) weather station, copied from our Yamagata page, next to each month's share of Yamagata's guest nights (Japan Tourism Agency, 2025). These are long-term averages, not a forecast.

Yamagata: average weather by month, 1991 to 2020, and share of 2025 visits
MonthAverage highAverage lowRainRainy daysDaylight on the 15thShare of 2025
January3.3 °C−3.1 °C88 mm15.7 days9 h 50 min7.4%
February4.4 °C−3.1 °C63 mm12.2 days10 h 50 min7.1%
March9.1 °C−0.3 °C72 mm11.5 days11 h 55 min7.8%
April16.4 °C4.7 °C64 mm9.2 days13 h 10 min6.8%
May22.6 °C10.7 °C74 mm8.7 days14 h 15 min8.6%
June25.9 °C15.7 °C105 mm9.9 days14 h 50 min8.3%
July29.1 °C20.0 °C187 mm12.7 days14 h 35 min8.8%
August30.5 °C20.9 °C153 mm10.5 days13 h 40 min11.3%
September25.8 °C16.6 °C124 mm10.1 days12 h 25 min8.5%
October19.5 °C9.8 °C105 mm9.6 days11 h 15 min9.8%
November12.6 °C3.6 °C74 mm11.4 days10 h 5 min8.4%
December6.1 °C−0.7 °C97 mm15.2 days9 h 30 min7.3%

Golden hour

Evening golden hour is our calculation for the 15th of each month of 2026: the time the sun takes to go from 6° above to 4° below the horizon (there is no official definition).

Yamagata: golden hour and sea temperature by month
MonthEvening golden hour (15th)
January0 h 58 min
February0 h 53 min
March0 h 51 min
April0 h 52 min
May0 h 56 min
June0 h 59 min
July0 h 57 min
August0 h 53 min
September0 h 51 min
October0 h 52 min
November0 h 56 min
December1 h 0 min

Public holidays by month

National public holidays from the official list on our holiday page, by month, so you can see them next to the weather and how busy each month was. Regional and local holidays are not included.

Public holidays by month, 2026 and 2027
Month20262027
January1 Jan: New Year's Day, 12 Jan: Coming-of-Age Day1 Jan: New Year's Day, 11 Jan: Coming-of-Age Day
February11 Feb: National Foundation Commemoration Day, 23 Feb: Emperor's Birthday11 Feb: National Foundation Commemoration Day, 23 Feb: Emperor's Birthday
March20 Mar: Vernal Equinox Day21 Mar: Vernal Equinox Day, 22 Mar: Public holiday (Vernal Equinox Day fell on a Sunday)
April29 Apr: Showa Day29 Apr: Showa Day
May3 May: Constitution Memorial Day, 4 May: Greenery Day, 5 May: Children's Day, 6 May: Public holiday (Constitution Memorial Day fell on a Sunday)3 May: Constitution Memorial Day, 4 May: Greenery Day, 5 May: Children's Day
July20 Jul: Marine Day19 Jul: Marine Day
August11 Aug: Mountain Day11 Aug: Mountain Day
September21 Sep: Respect for the Aged Day, 22 Sep: Public holiday (between Respect for the Aged Day and Autumnal Equinox Day), 23 Sep: Autumnal Equinox Day20 Sep: Respect for the Aged Day, 23 Sep: Autumnal Equinox Day
October12 Oct: Sports Day11 Oct: Sports Day
November3 Nov: Culture Day, 23 Nov: Labor Thanksgiving Day3 Nov: Culture Day, 23 Nov: Labor Thanksgiving Day

The quietest and busiest months

In 2025, April was Yamagata's quietest month (6.8% of the year's guest nights): average high 16.4 °C, average low 4.7 °C, 64 mm of rain. August was the busiest (11.3%): average high 30.5 °C, average low 20.9 °C, 153 mm of rain. The figures do not show that the weather makes a month busier or quieter, so we do not say it does.

Similar weather, quieter: ideas for August

August was Yamagata's busiest month in 2025 (11.3% of its guest nights). These places had an average high within 2 °C and rainy days within 3 of Yamagata's in August, in a different prefecture, and August took a smaller share of its 2025 guest nights than August did of Yamagata's:

  • Fukushima: average high 30.5 °C, 11.0 rainy days; August was 10.9% of Fukushima's year.
  • Kanazawa, Ishikawa: average high 31.3 °C, 9.3 rainy days; August was 10.1% of Ishikawa's year.
  • Matsue, Shimane: average high 31.6 °C, 9.6 rainy days; August was 11.3% of Shimane's year.
  • Nagasaki: average high 31.9 °C, 9.9 rainy days; August was 10.5% of Nagasaki's year.
  • Shizuoka: average high 31.3 °C, 9.0 rainy days; August was 11.3% of Shizuoka's year.

Weather: 1991–2020 averages at each city's weather station (World Meteorological Organization normals in Europe, Japan Meteorological Agency in Japan); a rainy day has at least 1 mm of rain. “Quieter” compares a month with the rest of that place's own year. Try another month or place. All quieter alternatives to Yamagata in August.

What these figures are

One weather station stands for Yamagata; places nearby can differ, especially by height or distance from the sea. For the full picture of Yamagata, including regions and holidays, see our Yamagata page; for other places, the visual guides and golden hour by place.

Where the Yamagata (山形) weather station is: 38.255° N, 140.345° E. Outline of Japan from Natural Earth (world-atlas), simplified; small islands may not show.

Key takeaways

  • Warmest month: August (average high 30.5 °C); coldest: January and February (average low −3.1 °C).
  • Wettest month: July (187 mm); driest: February (63 mm).
  • In 2025, April was Yamagata's quietest month for visitors and August the busiest.

Sources

Weather normals and daylight copied from our country or prefecture page; tourism shares from the same page. See how we research.

  1. Weather: 出典:気象庁ホームページ(山形 平年値). Japan Meteorological Agency, 1991–2020 normals for the Yamagata station: daily maximum and minimum temperature, precipitation, days with at least 1.0 mm of precipitation (降水量の階級日数) and hours of sunshine (日照時間). Accessed 22 September 2026. Licensed under PDL1.0. 気象庁「平年値」を加工して作成 — edited by Traveloffsy (English wording, selection and rounding).
  2. Daylight: our calculation of the time from sunrise to sunset on the 15th of each month of 2026 at the weather station's location, by the method of the NOAA Solar Calculator (NOAA Global Monitoring Laboratory, “Solar Calculation Details”, based on Jean Meeus, Astronomical Algorithms, allowing 0.833° for refraction and the size of the sun). Read it. Checked 22 September 2026. NOAA notes that calculated times can differ from what is observed.
  3. Source: 「宿泊旅行統計調査」(観光庁) (Overnight Travel Statistics Survey, Japan Tourism Agency), 2025 annual figures (final), tables 2 and 8 and reference table 1, published 6 July 2026. Survey page · workbook. Accessed 17 September 2026. Licensed under the Public Data License 1.0 (PDL1.0).

Modified data: the arrangement, the golden-hour and sea columns and the quietest/busiest comparison are ours, from the cited figures.