When does the tick season start and end? - briefly
Tick activity typically begins in early spring, around April, and continues until late autumn, usually ending by October or early November depending on climate. In warmer regions the period may start earlier and extend later.
When does the tick season start and end? - in detail
Tick activity generally follows a seasonal pattern driven by temperature and humidity. In most temperate regions, the period begins when daytime temperatures consistently reach 10 °C (50 °F) and humidity stays above 70 %. This threshold is typically met in early spring, around March to early April in the northern United States and southern Canada, and in late April to early May in more northern latitudes such as New England and the Great Lakes area.
The season extends until temperatures fall below the 10 °C threshold and leaf litter dries out, usually in late autumn. In the United States, activity often tapers off by October in the south and by early November in the north. In Europe, the start is similar—late March in the United Kingdom and early April in Scandinavia—while the end occurs in September in northern Scandinavia and in November in the Mediterranean basin.
Key factors influencing the exact timing include:
- Species: Ixodes scapularis (black‑legged tick) becomes active earlier in the south than Ixodes ricinus (European castor bean tick), which may have a later onset in cooler climates.
- Microclimate: Shaded, moist habitats such as forest edges and leaf litter prolong activity, allowing ticks to remain active for several weeks beyond the regional average.
- Altitude: Higher elevations experience delayed onset and earlier cessation due to cooler temperatures.
Peak activity, when questing rates are highest, typically occurs during the warmest months:
- Southern regions: May – July
- Mid‑latitude regions: June – August
- Northern regions: July – September
Preventive measures—such as wearing protective clothing, using repellents, and performing regular body checks—should commence at the first sign of sustained temperatures above 10 °C and continue until the last day of detectable questing activity. Monitoring local health department alerts provides region‑specific updates on tick activity trends.