Climate and Average Weather Year Round in Grójec Poland

In Grójec, the summers are comfortable and partly cloudy and the winters are long, freezing, snowy, windy, and mostly cloudy. Over the course of the year, the temperature typically varies from 24°F to 76°F and is rarely below 7°F or above 86°F.

Based on the tourism score, the best time of year to visit Grójec for warm-weather activities is from mid June to late August.

The warm season lasts for 3.6 months, from May 21 to September 8, with an average daily high temperature above 67°F. The hottest month of the year in Grójec is July, with an average high of 75°F and low of 56°F.

The cold season lasts for 3.7 months, from November 18 to March 9, with an average daily high temperature below 41°F. The coldest month of the year in Grójec is January, with an average low of 24°F and high of 33°F.

In Grójec, 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 Grójec begins around April 5 and lasts for 6.4 months, ending around October 17.

The clearest month of the year in Grójec is July, during which on average the sky is clear, mostly clear, or partly cloudy 57% of the time.

The cloudier part of the year begins around October 17 and lasts for 5.6 months, ending around April 5.

The cloudiest month of the year in Grójec is December, during which on average the sky is overcast or mostly cloudy 70% 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 Grójec varies throughout the year.

The wetter season lasts 3.7 months, from May 5 to August 28, with a greater than 23% chance of a given day being a wet day. The month with the most wet days in Grójec is July, with an average of 9.2 days with at least 0.04 inches of precipitation.

The drier season lasts 8.3 months, from August 28 to May 5. The month with the fewest wet days in Grójec is January, with an average of 5.1 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 Grójec is July, with an average of 9.2 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 31% on July 16.

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. Grójec experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year in Grójec. The month with the most rain in Grójec is July, with an average rainfall of 2.2 inches.

The month with the least rain in Grójec is February, 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. Grójec experiences some seasonal variation in monthly snowfall.

The snowy period of the year lasts for 4.0 months, from November 16 to March 17, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Grójec is February, with an average snowfall of 2.0 inches.

The snowless period of the year lasts for 8.0 months, from March 17 to November 16. The least snow falls around July 23, with an average total accumulation of 0.0 inches.

The length of the day in Grójec varies extremely over the course of the year. In 2024, the shortest day is December 21, with 7 hours, 46 minutes of daylight; the longest day is June 20, with 16 hours, 43 minutes of daylight.

The earliest sunrise is at 4:16 AM on June 16, and the latest sunrise is 3 hours, 27 minutes later at 7:44 AM on December 30. The earliest sunset is at 3:25 PM on December 12, and the latest sunset is 5 hours, 34 minutes later at 8:59 PM on June 24.

Daylight saving time (DST) is observed in Grójec during 2024, starting in the spring on March 31, lasting 6.9 months, and ending in the fall on October 27.

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.

The perceived humidity level in Grójec, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 3% of 3% throughout.

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 Grójec experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 5.7 months, from October 14 to April 6, with average wind speeds of more than 10.1 miles per hour. The windiest month of the year in Grójec is January, with an average hourly wind speed of 11.7 miles per hour.

The calmer time of year lasts for 6.3 months, from April 6 to October 14. The calmest month of the year in Grójec is August, with an average hourly wind speed of 8.5 miles per hour.

The predominant average hourly wind direction in Grójec varies throughout the year.

The wind is most often from the east for 2.0 weeks, from April 22 to May 6, with a peak percentage of 28% on April 25. The wind is most often from the north for 3.3 weeks, from May 6 to May 29, with a peak percentage of 30% on May 27. The wind is most often from the west for 11 months, from May 29 to April 22, with a peak percentage of 50% on January 1.

To characterize how pleasant the weather is in Grójec 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 Grójec for general outdoor tourist activities is from mid June to late August, 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 Grójec for hot-weather activities is from early July to mid August, with a peak score in the last week of July.

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 Grójec typically lasts for 5.7 months (175 days), from around April 22 to around October 14, rarely starting before April 5 or after May 11, and rarely ending before September 26 or after November 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 in Grójec should appear around April 27, only rarely appearing before April 19 or after May 9.

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 extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.6 months, from April 28 to August 16, with an average daily incident shortwave energy per square meter above 5.2 kWh. The brightest month of the year in Grójec is June, with an average of 6.3 kWh.

The darker period of the year lasts for 3.8 months, from October 24 to February 18, with an average daily incident shortwave energy per square meter below 1.8 kWh. The darkest month of the year in Grójec is December, with an average of 0.7 kWh.

For the purposes of this report, the geographical coordinates of Grójec are 51.863 deg latitude, 20.868 deg longitude, and 502 ft elevation.

The topography within 2 miles of Grójec contains only modest variations in elevation, with a maximum elevation change of 167 feet and an average elevation above sea level of 484 feet. Within 10 miles also contains only modest variations in elevation (354 feet). Within 50 miles contains only modest variations in elevation (1,312 feet).

The area within 2 miles of Grójec is covered by cropland (73%) and artificial surfaces (20%), within 10 miles by cropland (75%) and trees (15%), and within 50 miles by cropland (56%) and trees (27%).