Weather changes a simulated race the same way it changes a real one: rain cuts grip and visibility, a drying track opens a new, faster line, and temperature changes how much grip the track and tires offer. Modern sims model this dynamically. iRacing added rain in 2024, and Assetto Corsa Competizione lets track wetness rise and fall with rain intensity, sun and temperature, so you have to keep adjusting your braking points and line during a session.
What rain does in the real world
Rain matters on public roads as well as on track. The U.S. Federal Highway Administration lists reduced visibility, lower pavement friction and reduced vehicle traction among the effects of precipitation, and reports that over 77 percent of weather-related crashes happen in rain or mist (FHWA). In racing, Pirelli says its intermediate tires suit a wet track without standing water or a drying surface, while full wets are built to disperse large amounts of water and resist aquaplaning. In heavy rain, it notes, visibility rather than grip can become the problem (Pirelli).
How simulators model weather
iRacing
iRacing introduced its weather system in 2024 Season 2, with dynamic options including rain and fog. Water interacts with the track and tires, which pushes drivers onto alternate lines, and spray from other cars affects visibility. You can set cloud cover, moisture, temperature, wind, humidity and fog, or use forecasted weather where rain can arrive mid-session and a radar shows what is coming (iRacing). Even without rain, iRacing's dynamic track rubbers in along the racing line and heats in the sun, so shaded sections can offer more grip on a hot day (iRacing).
Assetto Corsa Competizione
Built around the GT World Challenge, ACC runs races across a full 24-hour cycle under a dynamic weather system. Rubber and marbles build up as cars run, and track wetness depends on rain intensity, sun and temperature (KUNOS Simulazioni). The series organizer highlights the famously unpredictable weather at Spa as part of the game (GT World Challenge).
Assetto Corsa and AC EVO
The original Assetto Corsa focuses on light rather than rain: its time-of-day mode calculates sun position from the track's real coordinates (Steam). KUNOS says Assetto Corsa EVO adds dynamic weather (KUNOS).
Driving in the wet: what changes
- Brake earlier and more gently. Lower grip means longer stopping distances and earlier lock-ups.
- Change your line. The rubbered-in dry line can be slippery when wet; iRacing notes that water pushes drivers to find grip on alternate lines.
- Be smooth. Sudden steering or throttle inputs are more likely to exceed the grip available.
- Watch the track dry. In ACC, wetness falls with sun and temperature, and Pirelli builds its intermediates for exactly that drying phase.
- Pick references you can still see. iRacing models spray that reduces visibility, so distant braking boards may disappear.
Night racing
Darkness mainly affects what you can see, so braking markers and apexes are harder to pick out. ACC's 24-hour cycle and AC's time-of-day lighting both let you practice this.
Weather at an event
For guests who have never driven a simulator, dry daylight conditions are the easier start; rain and night work well as a later challenge round once people know the track. SimsForHire brings full-motion rigs to corporate events, private parties and brand activations, staffed for the whole event. See experiences, pricing ($2,750 per full-motion rig per day, plus tax and insurance), or call (754) 228-5654.