Climate and Average Weather Year Round in Hwaseong-si South Korea

In Hwaseong-si, the summers are warm, muggy, and wet; the winters are short, freezing, snowy, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 19°F to 85°F and is rarely below 8°F or above 91°F.

Based on the tourism score, the best times of year to visit Hwaseong-si for warm-weather activities are from late May to early July and from mid August to late September.

The hot season lasts for 3.9 months, from May 28 to September 23, with an average daily high temperature above 75°F. The hottest month of the year in Hwaseong-si is August, with an average high of 84°F and low of 72°F.

The cold season lasts for 3.0 months, from December 1 to February 29, with an average daily high temperature below 44°F. The coldest month of the year in Hwaseong-si is January, with an average low of 19°F and high of 35°F.

In Hwaseong-si, 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 in Hwaseong-si begins around September 10 and lasts for 5.9 months, ending around March 6.

The clearest month of the year in Hwaseong-si is October, during which on average the sky is clear, mostly clear, or partly cloudy 70% of the time.

The cloudier part of the year begins around March 6 and lasts for 6.1 months, ending around September 10.

The cloudiest month of the year in Hwaseong-si is July, during which on average the sky is overcast or mostly cloudy 53% 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 in Hwaseong-si varies significantly throughout the year.

The wetter season lasts 2.8 months, from June 18 to September 11, with a greater than 30% chance of a given day being a wet day. The month with the most wet days in Hwaseong-si is July, with an average of 15.4 days with at least 0.04 inches of precipitation.

The drier season lasts 9.2 months, from September 11 to June 18. The month with the fewest wet days in Hwaseong-si is January, with an average of 3.0 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 in Hwaseong-si is July, with an average of 15.4 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 52% on July 21.

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. Hwaseong-si experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in Hwaseong-si. The month with the most rain in Hwaseong-si is July, with an average rainfall of 11.0 inches.

The month with the least rain in Hwaseong-si is January, with an average rainfall of 0.5 inches.

Snowfall

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

The snowy period of the year lasts for 1.6 months, from December 20 to February 8, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Hwaseong-si is January, with an average snowfall of 1.4 inches.

The snowless period of the year lasts for 10 months, from February 8 to December 20. The least snow falls around July 14, with an average total accumulation of 0.0 inches.

The length of the day in Hwaseong-si varies significantly over the course of the year. In 2024, the shortest day is December 21, with 9 hours, 36 minutes of daylight; the longest day is June 21, with 14 hours, 44 minutes of daylight.

The earliest sunrise is at 5:11 AM on June 13, and the latest sunrise is 2 hours, 35 minutes later at 7:47 AM on January 7. The earliest sunset is at 5:15 PM on December 6, and the latest sunset is 2 hours, 42 minutes later at 7:57 PM on June 28.

Daylight saving time (DST) is not observed in Hwaseong-si 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.

Hwaseong-si experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 3.1 months, from June 13 to September 17, during which time the comfort level is muggy, oppressive, or miserable at least 24% of the time. The month with the most muggy days in Hwaseong-si is July, with 27.3 days that are muggy or worse.

The least muggy day of the year is February 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 in Hwaseong-si experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 6.7 months, from October 21 to May 11, with average wind speeds of more than 8.7 miles per hour. The windiest month of the year in Hwaseong-si is December, with an average hourly wind speed of 10.3 miles per hour.

The calmer time of year lasts for 5.3 months, from May 11 to October 21. The calmest month of the year in Hwaseong-si is June, with an average hourly wind speed of 7.0 miles per hour.

The predominant average hourly wind direction in Hwaseong-si varies throughout the year.

The wind is most often from the west for 4.5 months, from February 22 to July 7, with a peak percentage of 45% on April 8. The wind is most often from the east for 1.6 months, from August 11 to September 28, with a peak percentage of 35% on September 7. The wind is most often from the north for 4.8 months, from September 28 to February 22, with a peak percentage of 53% on January 1.

Hwaseong-si 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 3.1 months, from July 5 to October 9, with an average temperature above 68°F. The month of the year in Hwaseong-si with the warmest water is August, with an average temperature of 75°F.

The time of year with cooler water lasts for 3.7 months, from December 24 to April 16, with an average temperature below 47°F. The month of the year in Hwaseong-si with the coolest water is February, with an average temperature of 40°F.

To characterize how pleasant the weather is in Hwaseong-si 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 times of year to visit Hwaseong-si for general outdoor tourist activities are from late May to early July and from mid August to late September, with a peak score in the second week of June.

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 Hwaseong-si for hot-weather activities is from mid 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 in Hwaseong-si typically lasts for 7.3 months (222 days), from around March 31 to around November 7, rarely starting before March 16 or after April 15, and rarely ending before October 22 or after November 24.

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 in Hwaseong-si should appear around April 15, only rarely appearing before April 6 or after April 24.

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 3.6 months, from April 16 to August 4, with an average daily incident shortwave energy per square meter above 5.7 kWh. The brightest month of the year in Hwaseong-si is May, with an average of 6.3 kWh.

The darker period of the year lasts for 2.9 months, from November 6 to February 3, with an average daily incident shortwave energy per square meter below 3.1 kWh. The darkest month of the year in Hwaseong-si is December, with an average of 2.3 kWh.

For the purposes of this report, the geographical coordinates of Hwaseong-si are 37.207 deg latitude, 126.817 deg longitude, and 62 ft elevation.

The topography within 2 miles of Hwaseong-si contains significant variations in elevation, with a maximum elevation change of 587 feet and an average elevation above sea level of 156 feet. Within 10 miles contains significant variations in elevation (1,033 feet). Within 50 miles contains very significant variations in elevation (4,032 feet).

The area within 2 miles of Hwaseong-si is covered by cropland (43%), trees (35%), and grassland (17%), within 10 miles by cropland (26%) and water (23%), and within 50 miles by water (31%) and trees (25%).