The majority of the County has a traditional continental climate with four distinct seasons. Summers are generally hot and humid, with frequent thunderstorms, while winters tend to be cool to cold. Snow is common in the hills and northern plains, but less likely in the southern plains, where winters are milder. Extreme weather is rare, although tornadoes do occur on the southern plains.
In the summer, County highs average in the mid- to high-80’s, dipping into the 60’s at night. In the winter, daytime highs are as frequently above freezing as below, while nighttime lows often dip into the teens.
The County is very humid, particularly in the morning, when humidity averages 80-90%, though the afternoons tend to be less humid, in the 50-70% range (highest in the winter months). In the south, the constant breeze off Wooly Bay protects the south shore area from this high humidity . Consequently, although temperatures on the south shore are the same as on the southern plains, the lower humidity gives the region a cooler feel. Inside the Mistmarsh, humidity remains universally high (80-90%) all day long.
The County receives almost 40 inches of precipitation annually, with mid-summer offering the fewest wet days (1 in 3) but the highest amount of falling precipitation (4″+/month), while mid-winter presents many more wet days (1 in 2), but the lowest precipitation totals (>2″/month). Snow has been recorded as early as November and as late as May, though is usually limited to December through March, with an average of 4-6″ falling in each month.
The entire north shore area, including all of Mavenshire, is heavily influenced by the presence of the Nyr Dyv, which (A.) keeps the region cooler than the rest of the north, (B.) gives it a higher annual and monthly precipitation totals than the rest of the County, and (C.) accounts for frequent morning fogs, with October through December being the foggiest months.
Tornado activity is limited almost exclusively to the spring and early summer, when an average of 20 per year will actually touch down. Of these, half (50%) can be classified as “weak”, causing damage over only a very limited area, and with relatively mild winds. Most of the rest (45%) are “strong”, which can cause devastating effects over a wider and longer path, with more destructive wind speeds. The final few (5%) will be “violent” storms, with the largest destructive footprint and most catastrophic wind speeds.
|Partly Cloudy Days|6|6|8|7|9|12|13|12|11|8|8|6|
|Days with Precipitation|12|11|14|12|11|11|9|9|8|8|11|12|
|Inches of Precipitation|2.25|1.75|2.50|3.25|2.75|4.00|4.25|4.00|3.00|2.75|3.00|3.00|
|Inches of Snowfall*|6.25|6.25|4.50|1.50|0.00|0.00|0.00|0.00|0.00|0.00|0.75|3.50|
|AM Humidity (%)|80|80|80|80|80|85|85|90|90|90|85|85|
|PM Humidity (%)|70|70|65|60|55|55|60|60|60|55|60|70|
*1″ of rain = 10″ of snow