Tetramorium immigrans
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
Outdoor activity responds to seasonal warming, while colonies beside heated buildings may become active unusually early. Winter indoor swarms should be investigated rather than treated as normal outdoor timing.
In the Northern Hemisphere, mating flights are commonly reported from late May through July, often near sunrise on still days. Local weather changes the timing. [ID, Pavement]
The nest has its own climate
Concrete can be much warmer than shaded soil. Compare shaded and sunny entrances at matched times, and record surface temperature separately from the weather-station air temperature.
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.