This report describes the typical weather at the Geraldton (Greenstone Regional) Airport (Geraldton, Ontario, Canada) weather station over the course of an average year. It is based on the historical records from 1983 to 2012. Earlier records are either unavailable or unreliable.
Geraldton, Ontario has a humid continental climate with warm summers and no dry season. The area within 25 mi of this station is covered by forests (92%) and lakes and rivers (8%).
Over the course of a year, the temperature typically varies from -13°F to 71°F and is rarely below -32°F or above 82°F.
The warm season lasts from May 22 to September 15 with an average daily high temperature above 59°F. The hottest day of the year is July 23, with an average high of 71°F and low of 51°F.
The cold season lasts from November 29 to March 2 with an average daily high temperature below 21°F. The coldest day of the year is January 23, with an average low of -13°F and high of 10°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 8:07 hours of daylight; the longest day is June 20 with 16:19 hours of daylight.
The earliest sunrise is at 5:38am on June 13 and the latest sunset is at 10:00pm on June 27. The latest sunrise is at 8:46am on December 30 and the earliest sunset is at 4:46pm on December 12.
Daylight savings time (DST) is observed in this location during 2012, starting in the spring on March 11 and ending in the fall on November 4.
The median cloud cover ranges from 77% (partly cloudy) to 98% (overcast). The sky is cloudiest on November 18 and clearest on August 7. The clearer part of the year begins around January 16. The cloudier part of the year begins around September 23.
On August 7, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 42% of the time, and overcast or mostly cloudy 55% of the time.
On November 18, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 82% of the time, and clear or mostly clear 16% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around December 2, occurring in 83% of days. Precipitation is least likely around April 10, occurring in 52% of days.
Over the entire year, the most common forms of precipitation are light snow, light rain, moderate snow, and thunderstorms.
Light snow is the most severe precipitation observed during 45% of those days with precipitation. It is most likely around December 26, when it is observed during 65% of all days.
Light rain is the most severe precipitation observed during 21% of those days with precipitation. It is most likely around September 2, when it is observed during 27% of all days.
Moderate snow is the most severe precipitation observed during 11% of those days with precipitation. It is most likely around December 1, when it is observed during 15% of all days.
Thunderstorms are the most severe precipitation observed during 11% of those days with precipitation. They are most likely around July 18, when it is observed during 23% of all days.
During the warm season, which lasts from May 22 to September 15, there is a 59% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (43% of days with precipitation have at worst light rain), thunderstorms (30%), and moderate rain (17%).
During the cold season, which lasts from November 29 to March 2, there is a 77% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light snow (79% of days with precipitation have at worst light snow) and moderate snow (17%).
The likelihood of snow falling is highest around December 25, occurring in 81% of days. The season in which it is relatively likely for snow to fall spans from October 5 to April 28.
During peak snow season, accumulation at this location on a given day is just more likely than not. The chances of there being snow on the ground are highest around February 25, occurring 64% of the time. The season in which snow is relatively likely to be on the ground spans from October 26 to April 29.
The snow is typically at its deepest on March 6, with a median depth of 19.9"; the depth exceeds 28.6" only one year out of ten.
The relative humidity typically ranges from 40% (comfortable) to 97% (very humid) over the course of the year, rarely dropping below 21% (dry) and reaching as high as 100% (very humid).
The air is driest around April 27, at which time the relative humidity drops below 49% (comfortable) three days out of four; it is most humid around September 21, exceeding 94% (very humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a year, the dew point typically varies from -19°F (dry) to 56°F (comfortable) and is rarely below -40°F (dry) or above 66°F (muggy).
The time of the year between June 15 and September 8 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of the year typical wind speeds vary from 0 mph to 15 mph (calm to moderate breeze), rarely exceeding 20 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around May 15, at which time the average daily maximum wind speed is 15 mph (moderate breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around December 17, at which time the average daily maximum wind speed is 12 mph (gentle breeze).