Climatological Data
Since Boston is bordered by Boston Harbor and the Atlantic Ocean, its coastal climate tends to be more moderate than inland locations -- Boston rarely experiences either extreme heat or cold. In the winter, the first freezing temperatures usually occur in early November, but the temperatures are modified considerably by the nearness of the relatively warm ocean. Frigid weather usually fades out by early April, and Boston typically enjoys a spectacular, colorful spring with moderate temperatures. Although it can get quite warm in the summer, the hot afternoons frequently are tempered by the eastern sea breezes, as air flows inland from the cooler surfaces of the ocean.

Temperature
The spring and summer months of April through June and the early fall months of September through mid-November are the most enjoyable, temperate seasons. Bostonians experience their coldest months during January and February (with a mean temperature of about 29 degrees) and their warmest months during July and August (with a mean around 72 degrees). Freezing temperatures are common from late November to late March. By May, the temperatures rise to a moderate 60-70 degrees, then reach even higher numbers (sometimes 90 degrees and over) during July and August.

Average Temperature

Jan	Feb	Mar	Apr	May	June	July	Aug	Sept	Oct	Nov	Dec
28.8	29.4	37.1	47.2	57.9	67.2	72.7	71	64.1	54.0	43.7	32.8

Precipitation and Snowfall
Boston has no true dry season as it rains intermittently throughout the year. Much of the rainfall during the summer and early fall comes from showers and thunderstorms. At other times during the year, low pressure systems pass frequently and produce rain, on average, one out of three days. Coastal storms-which Bostonians refer to as "Northeasters"-produce much of the rain and snow. The main snow season occurs from December through March.

Rainfall (average in inches)

Jan	Feb	Mar	Apr	May	June	July	Aug	Sept	Oct	Nov	Dec
3.62	3.38	3.86	3.61	3.22	3.15	3.15	3.60	3.19	3.29	3.91	3.65

Snowfall (average in inches)

Jan	Feb	Mar	Apr	May	June	July	Aug	Sept	Oct	Nov	Dec
12.0	11.3	7.9	0.9	0	0	0	0	0	0	1.3	7.5

Wind and Relative Humidity
Because of its moderate coastal weather systems, Boston is not known to suffer from particularly windy weather. Although winds of 30 miles per hour or higher may occur anytime during the year, gales happen more frequently and severely during the winter. While relative humidity has fallen as low as 5%, such dryness is quite rare. Boston does experience heavy fog on average two days a month, which occurrence increases at locations nearer to the coast.