Climate and Average Weather Year Round in Alpiarça Portugal

In Alpiarça, the summers are hot, dry, and mostly clear and the winters are cold, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 41°F to 91°F and is rarely below 33°F or above 104°F.

Based on the beach/pool score, the best time of year to visit Alpiarça for hot-weather activities is from late June to early September.

The hot season lasts for 3.0 months, from June 19 to September 18, with an average daily high temperature above 84°F. The hottest month of the year in Alpiarça is August, with an average high of 89°F and low of 63°F.

The cool season lasts for 3.6 months, from November 15 to March 4, with an average daily high temperature below 65°F. The coldest month of the year in Alpiarça is January, with an average low of 42°F and high of 59°F.

In Alpiarça, 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 Alpiarça begins around June 5 and lasts for 3.3 months, ending around September 14.

The clearest month of the year in Alpiarça is July, during which on average the sky is clear, mostly clear, or partly cloudy 89% of the time.

The cloudier part of the year begins around September 14 and lasts for 8.7 months, ending around June 5.

The cloudiest month of the year in Alpiarça is December, during which on average the sky is overcast or mostly cloudy 51% 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 Alpiarça varies throughout the year.

The wetter season lasts 8.0 months, from September 24 to May 23, with a greater than 17% chance of a given day being a wet day. The month with the most wet days in Alpiarça is November, with an average of 8.8 days with at least 0.04 inches of precipitation.

The drier season lasts 4.0 months, from May 23 to September 24. The month with the fewest wet days in Alpiarça is July, with an average of 0.9 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 Alpiarça is November, with an average of 8.8 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 31% on October 30.

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. Alpiarça experiences significant seasonal variation in monthly rainfall.

The rainy period of the year lasts for 9.7 months, from August 29 to June 18, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Alpiarça is November, with an average rainfall of 3.3 inches.

The rainless period of the year lasts for 2.3 months, from June 18 to August 29. The month with the least rain in Alpiarça is July, with an average rainfall of 0.1 inches.

The length of the day in Alpiarça varies significantly over the course of the year. In 2024, the shortest day is December 21, with 9 hours, 24 minutes of daylight; the longest day is June 20, with 14 hours, 56 minutes of daylight.

The earliest sunrise is at 6:07 AM on June 14, and the latest sunrise is 1 hour, 49 minutes later at 7:56 AM on October 26. The earliest sunset is at 5:11 PM on December 6, and the latest sunset is 3 hours, 54 minutes later at 9:04 PM on June 27.

Daylight saving time (DST) is observed in Alpiarça 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 Alpiarça, 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 2% of 2% 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 Alpiarça experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 5.5 months, from March 7 to August 21, with average wind speeds of more than 8.6 miles per hour. The windiest month of the year in Alpiarça is July, with an average hourly wind speed of 9.2 miles per hour.

The calmer time of year lasts for 6.5 months, from August 21 to March 7. The calmest month of the year in Alpiarça is September, with an average hourly wind speed of 8.0 miles per hour.

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

The wind is most often from the north for 9.5 months, from February 9 to November 24, with a peak percentage of 64% on July 21. The wind is most often from the east for 2.5 months, from November 24 to February 9, with a peak percentage of 34% on January 1.

Alpiarça 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 some seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.9 months, from June 24 to October 19, with an average temperature above 64°F. The month of the year in Alpiarça with the warmest water is August, with an average temperature of 66°F.

The time of year with cooler water lasts for 3.7 months, from December 31 to April 21, with an average temperature below 59°F. The month of the year in Alpiarça with the coolest water is February, with an average temperature of 58°F.

To characterize how pleasant the weather is in Alpiarça 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 Alpiarça for general outdoor tourist activities is from early May to mid October, with a peak score in the last 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 Alpiarça for hot-weather activities is from late June to early September, 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 Alpiarça typically lasts for 11 months (325 days), from around January 30 to around December 20, rarely starting after March 1, or ending before November 18.

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 Alpiarça should appear around February 1, only rarely appearing before January 21 or after February 14.

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 3.2 months, from May 14 to August 20, with an average daily incident shortwave energy per square meter above 6.9 kWh. The brightest month of the year in Alpiarça is July, with an average of 8.0 kWh.

The darker period of the year lasts for 3.6 months, from October 25 to February 14, with an average daily incident shortwave energy per square meter below 3.2 kWh. The darkest month of the year in Alpiarça is December, with an average of 2.0 kWh.

For the purposes of this report, the geographical coordinates of Alpiarça are 39.257 deg latitude, -8.582 deg longitude, and 79 ft elevation.

The topography within 2 miles of Alpiarça contains only modest variations in elevation, with a maximum elevation change of 194 feet and an average elevation above sea level of 80 feet. Within 10 miles contains only modest variations in elevation (646 feet). Within 50 miles contains significant variations in elevation (2,339 feet).

The area within 2 miles of Alpiarça is covered by cropland (89%), within 10 miles by cropland (64%) and trees (31%), and within 50 miles by trees (42%) and cropland (41%).