Anderson has an invigorating climate because of its location in the middle latitudes and away from the influence of oceans. Contrasting cool north winds and warm south winds move back and forth across East-Central Indiana resulting in rainfall and frequent changes of temperature and humidity.

Anderson is on the warm side of this undulating boundary much of the time in the summer and on the cold side in winter. This activity causes low-pressure centers form and move across the plains, up the Ohio River Valley and the St. Lawrence River Valley to the Atlantic. Most of Anderson’s rainfall comes from these storms. Thunderstorms bring most of the summer rainfall either singly, scattered, or in line with fronts and weather changes. Days with thunderstorms average about seven a month in the summer and about two a year in the winter months. Although the area is subject to frequent storms, most violent mid-latitude, storms pass north and south of Anderson.

Relative humidity varies from the 40’s during a typical summer afternoon to 90 and higher just before dawn. Relative humidity rises and falls much as temperature does during a 24-hour period, but the highest percent usually occurs with the minimum temperature and the lowest percent with the maximum temperature. In the winter the most probable range of humidity from afternoon to night is from the 60’s to the 90’s. Fog is a visible indicator of humidity in the high 90’s and 100 percent and occurs most often during the winter months. The average day has a greater range of temperature in the summer than in the winter. The winter days have a daily temperature range of 17 degrees while in summer, the range is 25 degrees. J

uly is the warmest month of the year. An average July has 7 days of temperature reaching 90 degrees or higher. January is the coldest month. The winter season averages 4 days with the minimum temperatures below zero.

Prevailing winds in the Anderson area are from the southwest during the year, except in the winter and early spring when west and northwest directional winds prevail. Precipitation is least in the winter. The most rain comes in the late spring and early summer. Snowfall is light in some seasons and heavy in others. The average for a season is 17.9 inches.

The growing season (defined as the number of days between the last spring and the first fall temperature of 32 degrees) averages 178 days in length. The season is 200 days or more in 10% of the years, 190 days or more in 25% of the years and less than 166 days in 25% of the years, and less than 156 days in 10% of the years.

The White River flowing through Anderson occasionally floods low lands. The river gauge 275 feet downstream from the old 12th Street bridge read 23.6 feet on March 25, 1913. This is the highest stage of record commencing in 1904. The zero of the river gauge near the bottom of the river is 825.0 feet above sea level.