The USGS (U.S. Geological Survey) publishes a set of the most commonly used topographic maps of the U.S. called US Topo that are separated into rectangular quadrants that are printed at 22.75"x29" or larger. Number 2 Portal Lake Dam is covered by the Waltonville, IL US Topo Map quadrantFree US Topo Map PDF Order Waterproof Printed Topo Map
Below are weather averages from 1971 to 2000 according to data gathered from the nearest official weather station. The nearest weather station for both precipitation and temperature measurements is NASHVILLE 4 NE which is approximately 15 miles away and has an elevation of 515 feet (6 feet higher than Number 2 Portal Lake Dam). Because the nearest station and this geographic feature may have differences in elevation and topography, the historic weather at the two separate locations may be different as well.
|Month||Precip||AVG High Temp||AVG Low Temp|
This location's average summer high temps are higher than 59% of other locations on record.
This location's average winter low temps are higher than 58% of other locations on record.
This location's average precipitation levels are higher than 58% of other locations on record.