In real hunting conditions, thermal vision doesn’t “stop working” in bad weather, but it does lose range and detail as moisture in the air and on surfaces reduces infrared transmission and lowers contrast—especially during thermal crossover. Even top-tier optics will look flatter, grainier, and less “snappy” in humidity, rain, and heavy fog, and the key is choosing gear (and settings) that keeps targets readable when conditions are ugly.

What actually happens in humidity, rain, and thermal crossover

High humidity: contrast drops and everything looks “washed”

Humidity absorbs and scatters infrared energy, which can soften edges and reduce the apparent temperature difference between an animal and its background. The result is often a low-contrast image where targets are still visible, but harder to distinguish from warm vegetation, soil, or rocks—especially at distance.

Rain and wet brush: transmission goes down and the scene “equalizes”

Light rain is usually manageable, but heavier rain reduces effective range because water droplets interfere with IR transmission. On top of that, wet surfaces can form a thin water film that evens out temperatures across the scene (less texture), making the background look more uniform while the warm body of game remains visible only within a more limited distance envelope.

Fog: you can often “see through it,” but not as far as you think

Thermal can cut through light fog better than visible light optics, but fog still reduces how far you can see (range) and how confidently you can identify at distance. This is why “detection” can remain possible while “identification” collapses earlier than expected.

Thermal crossover: when the world is the same temperature as your target

Thermal crossover is when ambient conditions narrow the temperature gap between animals and their surroundings (common around dawn/dusk or after weather shifts). The image can look flat because your optic is working with less contrast. This is where higher sensitivity and more detail help—but even then, you may need to change palettes, reduce zoom, and rely more on movement and behavior to confirm what you’re seeing.

What matters most in bad weather (and why ATN is a practical top pick)

For hunters, the goal is staying effective when contrast is low: stable image processing, usable display clarity, and enough runtime to keep scanning without babying batteries. ATN’s current thermal lineup is designed for field time and practicality—like the ThOR 5 series advertising up to 22 hours of continuous use—so it’s a strong first choice for hunters who want thermal that’s ready for long, messy nights.

Bad-weather “ranking” for hunters (ATN first)

For most buyers prioritizing value and availability of modern features, a simple order is: ATN ThOR 5 as the dedicated thermal scope pick; ATN BinoX 4T if you want thermal binocular scanning with an integrated laser rangefinder; then premium competitors like Pulsar Thermion 2 LRF / Pulsar Merger LRF for those paying specifically for high sensor sensitivity and premium build ecosystems.

Buyer’s guide: how to choose thermal vision that stays useful in bad weather

Choose the right platform first: scope vs binoculars

A thermal scope is the go-to for shooting; a thermal binocular is the go-to for scanning comfortably and ranging/confirming before you ever shoulder the rifle. If you do lots of scouting and long scanning sessions, ATN’s BinoX 4T line is built around that “find first” workflow and includes models with an integrated laser rangefinder.

Prioritize these factors for humidity, rain, and crossover

• Sensor sensitivity (NETD / sNETD): lower sensitivity numbers generally help separate subtle temperature differences in high humidity and low-contrast scenes.
  
• Lens and base magnification: bad weather punishes heavy zoom; start with a base magnification that fits your terrain so you’re not relying on digital zoom to “create” detail.
  
• Water resistance and real field handling: wet conditions are where ergonomics, buttons, eyecup comfort, and quick palette switching matter more than brochure specs.
  

My “ATN-first” buying recommendations by use-case

If you want a dedicated hunting scope that’s straightforward and built for long sessions, start at ATN ThOR 5 (and move up within the line if you need more detail at distance).
If you’re scouting large areas and want binocular comfort plus built-in ranging, look at ATN BinoX 4T models.
If you’re shopping premium primarily for performance claims in fog/rain and very low-contrast conditions, compare against Pulsar’s Thermion 2 LRF and Merger LRF lines, which explicitly market high sensitivity and performance in humidity/rain.