Formica species
Indiana provides a seasonal outdoor setting, with freezing winters and warm summers. The table describes Lafayette weather; it is not a nest-temperature range or a laboratory tolerance limit for this ant.
Lafayette climate at a glance
Month | Mean °F | Mean °C | Precip in | Precip mm |
|---|---|---|---|---|
Jan | 25.8 | -3.4 | 2.19 | 56 |
Feb | 29.7 | -1.3 | 1.78 | 45 |
Mar | 40.0 | 4.4 | 2.73 | 69 |
Apr | 51.1 | 10.6 | 3.84 | 98 |
May | 61.6 | 16.4 | 4.04 | 103 |
Jun | 70.7 | 21.5 | 4.56 | 116 |
Jul | 73.6 | 23.1 | 4.08 | 104 |
Aug | 72.2 | 22.3 | 3.12 | 79 |
Sep | 65.5 | 18.6 | 2.59 | 66 |
Oct | 53.7 | 12.1 | 2.91 | 74 |
Nov | 41.3 | 5.2 | 2.87 | 73 |
Dec | 31.0 | -0.6 | 2.29 | 58 |
Seasonal activity
Record the first surface activity, major foraging periods, and winged-ant appearances separately. These are different biological events and need not respond identically to weather.
Many Midwestern field-ant swarms occur during summer and early autumn. This broad group has no single dependable flight month. [ID]
The nest has its own climate
Sun exposure can change a mound temperature rapidly. A warm mound top does not describe all chambers below it. Use nonintrusive surface readings and make that limitation explicit.
Sun, cover, soil depth, and indoor heating can shift exposure within a few steps. No single temperature or humidity target should be inferred from this regional climate table.
Weather extremes and future change
NOAA’s 2022 Indiana assessment projects warmer conditions and increased risks from heavy precipitation, while greater evaporation can intensify drought. These are regional projections; they do not predict the abundance of an individual ant species. [Climate]
Observation suggestion: record the first spring workers and each swarm with the date, time, recent rain, and location. Compare several years before attributing a change to climate rather than food availability, habitat change, or observation effort.