Florence County Climate Profile

Florence County is located in the northeastern part of Wisconsin, along the Michigan border. The county’s land cover is primarily a blend of forests, grasslands, and wetlands. Florence County has a humid continental climate, characterized by precipitation year-round and summers that are warm to hot.

Records are computed using all available station data, some of which goes back to 1895 (Source: ACIS).

Averages for freeze dates are computed for the most recent 30 years (1995-2024; Source: ACIS).

Temperatures have been increasing since 1950 in Florence County on the annual and seasonal time scales, which is the case for most of Wisconsin. Since 1950, annual average temperatures in Florence County have increased at a rate of 0.5°F/decade, which translates to an increase of 1°F every 20 years. This increase in temperature has been most pronounced in the winter months and less pronounced in the other seasons. When annual average temperatures are split into daily high and low temperatures, low temperatures have been warming at a faster rate compared to high temperatures. In particular, winter minimum temperatures have been increasing by 1°F every 13 years since 1950.

With temperatures warming, this does not mean that every year will be warmer than the last, or that more recent years will all have above-average (1895-2025) temperatures. However, Florence County is experiencing more years that are above average than it did in the past. For example, since 2000, Florence County has experienced only four years with below-average temperatures. Similarly, if we rank the top ten warmest years in Florence County since 1895 (black circles on the above chart), seven have occurred since 2000, with 1998 also in the top ten. The top ten coldest years (black squares) are a bit more spread out over time, with just one of the top ten years occurring since 2000.

On the annual timescale, precipitation has shown minimal change in Florence County since 1950. Precipitation has decreased at a rate of 0.14″ per decade, which means an decrease of one inch every 71 years. This decreasing trend is different from most other Wisconsin counties, which have gotten wetter since 1950. At the seasonal level, winter and spring have experienced little to no change in precipitation since 1950. Summer is the season of largest decrease in precipitation in terms of inches (0.27″ per decade) and percentage (15 percent). Fall has gotten wetter by 13% since 1950.

Looking at the full record from 1895 to 2025, annual precipitation has increased overall (one inch approximately every 48 years). However, unlike the top ten warmest years on record, the top ten wettest years on record are not clustered towards more-recent years. This mix of wet and dry years is normal within a long-term trend. Since 2000, for example, the county has had two of its wettest years on record (2017 and 2019), but it has also seen ten years with below-average precipitation. This year-to-year variability in annual precipitation points to the usefulness of long-term data sets when looking at climate trends.

Despite being one of Wisconsin’s northern counties, Florence County is no stranger to sweltering summer heat, where daytime temperatures can top 90°F or even 100°F. But when are these hot days most likely to occur in Florence County? The State Climatology Office analyzed the likelihood of a “hot day” (daily high temperature ≥ 90°F) or “warm night” (daily low temperature ≥ 70°F) occurring between two calendar dates using historical measured temperature data from NOAA stations in Florence County. Based on this analysis, hot days have occurred most frequently between July 11 to 31. Over the past 20 years (2006-2025), Florence County experiences, on average, two hot days per year. Warm nights are less common in Florence County, with an average of one warm night occurring every two years. Warm nights most frequently occur between July 1 to 10.

Have Florence County summers been getting hotter? Since 1950, summertime average temperatures have warmed by about 3°F, but have not warmed as much compared to other seasons in Florence County. Summertime low temperatures have warmed by about 4°F since 1950. By comparison, summer high temperatures in Florence County have not warmed as much (2°F). Also, the hottest temperature of the year in Florence County has not shown an increasing trend between 1950 and 2025. You can read more about trends in summertime temperatures in Wisconsin in this blog post.

Florence County can get quite chilly once winter rolls around! Some of our coldest days of the year in Wisconsin are when the overnight low temperatures dip below 0°F. The State Climatology Office performed an analysis on the likelihood of a “very cold day” (daily high temperature ≤ 10°F) or “very cold night” (daily low temperature ≤ 0°F) occurring between two calendar dates using historical measured temperature data from NOAA stations in Florence County. Based on this analysis, very cold days and nights have occurred most frequently between January 21 to 31. Over the past 20 years (2006-2025), Florence County experienced, on average, nine very cold days per year and 35 very cold nights per year.

Across all four seasons, winter has warmed the most in Florence County since 1950, a trend that holds true across most of Wisconsin. Since 1950, average winter temperatures in Florence County have warmed by 4-5°F. Over this same time period, low temperatures in winter have warmed a bit more than the average temperatures (approximately 6°F). The coldest temperature of the year in Florence County has shown a warming trend since 1950.

Heavy precipitation days, which for this publication refers to a one-day liquid precipitation total of two inches or more, can impact Florence County at all times of the year. Extreme precipitation in the winter is measured by the amount of liquid that would be present if you melted down all of the snow that fell that day. The vast majority of these heavy precipitation days (72 percent) have occurred from June through September. July is the month that has historically had the most heavy precipitation days in Florence County. In general, summer is the wettest season in Florence County, with winter being the driest season. Over the past 20 years (2006-2025), the county experienced, on average, six heavy precipitation days per decade.

Future climate projections from the Wisconsin Initiative on Climate Change Impacts (WICCI) indicate that by mid-century (2041-2060), under a moderate greenhouse gas emissions scenario, average annual temperatures in Florence County will continue to increase by approximately 4°F compared to recent averages. Winter is projected to continue to be the season of the largest temperature increase (about 5°F). The number of nights where temperatures drop below 0°F is expected to decrease as winters warm (20-25 nights per year), and the number of nights in summer with temperatures staying above 70°F is expected to increase. The frequency of days that top 90°F is projected to increase with a warming climate to 15-20 days per year.

Annual precipitation is expected to increase by around five percent by mid-century, according to WICCI projections. This is a flip from the decreasing trend that has been observed up to present day. Winter and spring are projected to be the seasons of greatest precipitation increase in Florence County (about 10 percent), with summers projected to be 5 percent drier by mid-century. Despite projections for drier summers, the frequency of heavy precipitation days (two inches or more) is projected to increase by mid-century. 

To explore more climate projections from WICCI and learn more about future climate modeling, please visit this website.

The data in this publication are a snapshot of the historical climate data for Florence County. If you have questions about this publication or would like more data on a topic, please contact the Wisconsin State Climatology Office. 

For more information about how climate affects your farm, community, health, and livelihood, please check out resources from the Division of Extension and the Wisconsin Initiative on Climate Change Impacts.