Climate and Average Weather Year Round at Ominato Ab Japan

At Ominato Ab, the summers are comfortable, humid, and wet; the winters are freezing, snowy, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 25°F to 78°F and is rarely below 18°F or above 86°F.

Based on the tourism score, the best time of year to visit Ominato Ab for warm-weather activities is from early July to early September.

The warm season lasts for 3.1 months, from June 22 to September 25, with an average daily high temperature above 69°F. The hottest month of the year at Ominato Ab is August, with an average high of 77°F and low of 67°F.

The cold season lasts for 3.4 months, from December 5 to March 19, with an average daily high temperature below 42°F. The coldest month of the year at Ominato Ab is January, with an average low of 26°F and high of 34°F.

At Ominato Ab, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year at Ominato Ab begins around September 13 and lasts for 2.9 months, ending around December 10.

The clearest month of the year at Ominato Ab is October, during which on average the sky is clear, mostly clear, or partly cloudy 65% of the time.

The cloudier part of the year begins around December 10 and lasts for 9.1 months, ending around September 13.

The cloudiest month of the year at Ominato Ab is January, during which on average the sky is overcast or mostly cloudy 65% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Ominato Ab varies throughout the year.

The wetter season lasts 5.6 months, from July 17 to January 5, with a greater than 32% chance of a given day being a wet day. The month with the most wet days at Ominato Ab is November, with an average of 11.7 days with at least 0.04 inches of precipitation.

The drier season lasts 6.4 months, from January 5 to July 17. The month with the fewest wet days at Ominato Ab is March, with an average of 7.8 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone at Ominato Ab is September, with an average of 10.8 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 38% on August 27.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Ominato Ab experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year at Ominato Ab. The month with the most rain at Ominato Ab is September, with an average rainfall of 5.1 inches.

The month with the least rain at Ominato Ab is February, with an average rainfall of 1.2 inches.

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Ominato Ab experiences significant seasonal variation in monthly snowfall.

The snowy period of the year lasts for 4.4 months, from November 18 to March 31, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow at Ominato Ab is February, with an average snowfall of 6.4 inches.

The snowless period of the year lasts for 7.6 months, from March 31 to November 18. The least snow falls around July 24, with an average total accumulation of 0.0 inches.

The length of the day at Ominato Ab varies significantly over the course of the year. In 2024, the shortest day is December 21, with 9 hours, 12 minutes of daylight; the longest day is June 21, with 15 hours, 9 minutes of daylight.

The earliest sunrise is at 4:01 AM on June 14, and the latest sunrise is 2 hours, 59 minutes later at 7:01 AM on January 4. The earliest sunset is at 4:06 PM on December 8, and the latest sunset is 3 hours, 6 minutes later at 7:12 PM on June 27.

Daylight saving time (DST) is not observed at Ominato Ab during 2024.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

Ominato Ab experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 2.4 months, from July 4 to September 16, during which time the comfort level is muggy, oppressive, or miserable at least 16% of the time. The month with the most muggy days at Ominato Ab is August, with 17.2 days that are muggy or worse.

The least muggy day of the year is March 13, when muggy conditions are essentially unheard of.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed at Ominato Ab experiences extreme seasonal variation over the course of the year.

The windier part of the year lasts for 5.7 months, from October 19 to April 9, with average wind speeds of more than 11.9 miles per hour. The windiest month of the year at Ominato Ab is January, with an average hourly wind speed of 16.2 miles per hour.

The calmer time of year lasts for 6.3 months, from April 9 to October 19. The calmest month of the year at Ominato Ab is July, with an average hourly wind speed of 7.5 miles per hour.

The predominant average hourly wind direction at Ominato Ab varies throughout the year.

The wind is most often from the east for 3.3 months, from June 2 to September 11, with a peak percentage of 49% on July 6. The wind is most often from the west for 8.7 months, from September 11 to June 2, with a peak percentage of 74% on January 1.

Ominato Ab is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences significant seasonal variation over the course of the year.

The time of year with warmer water lasts for 2.7 months, from July 21 to October 12, with an average temperature above 66°F. The month of the year at Ominato Ab with the warmest water is August, with an average temperature of 71°F.

The time of year with cooler water lasts for 3.8 months, from January 12 to May 6, with an average temperature below 49°F. The month of the year at Ominato Ab with the coolest water is March, with an average temperature of 43°F.

To characterize how pleasant the weather is at Ominato Ab throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Ominato Ab for general outdoor tourist activities is from early July to early September, with a peak score in the second week of August.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Ominato Ab for hot-weather activities is from late July to late August, with a peak score in the first week of August.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season at Ominato Ab typically lasts for 7.3 months (222 days), from around April 10 to around November 18, rarely starting before March 25 or after April 27, and rarely ending before November 3 or after December 4.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms at Ominato Ab should appear around May 11, only rarely appearing before May 2 or after May 23.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.

The brighter period of the year lasts for 4.0 months, from April 20 to August 18, with an average daily incident shortwave energy per square meter above 5.3 kWh. The brightest month of the year at Ominato Ab is June, with an average of 6.2 kWh.

The darker period of the year lasts for 3.2 months, from November 10 to February 16, with an average daily incident shortwave energy per square meter below 2.3 kWh. The darkest month of the year at Ominato Ab is December, with an average of 1.4 kWh.

For the purposes of this report, the geographical coordinates of Ominato Ab are 41.233 deg latitude, 141.133 deg longitude, and 16 ft elevation.

The topography within 2 miles of Ominato Ab contains significant variations in elevation, with a maximum elevation change of 735 feet and an average elevation above sea level of 87 feet. Within 10 miles contains significant variations in elevation (2,864 feet). Within 50 miles contains large variations in elevation (5,197 feet).

The area within 2 miles of Ominato Ab is covered by water (55%), trees (25%), and cropland (17%), within 10 miles by water (48%) and trees (38%), and within 50 miles by water (72%) and trees (20%).