The WiFi only works when it's raining (2024)

Original Article ↗ Hacker News Discussion ↗

RF behavior, rain, and Wi‑Fi links

  • Several commenters relate similar “works only in certain weather” RF issues: long-distance 2.4 GHz links improving in rain, cable internet failing only when it was both cold and raining, or only during snowmelt.
  • One theory: rain and fog attenuate background RF noise more than the strong point‑to‑point signal, effectively acting like “horse blinders” and cleaning up the link.
  • Others mention classic atmospheric effects (nighttime AM radio range, sporadic propagation) as an initial hypothesis.

Trees, water, and attenuation

  • Multiple anecdotes confirm trees and especially wet leaves can severely degrade GHz links; several people had point‑to‑point Wi‑Fi or TV antennas that worked great in winter but failed in leafy, rainy summers.
  • Commenters note water inside leaves is conductive and a good attenuator at these frequencies.
  • One side claims 2.4 GHz is chosen because water absorbs strongly there; another replies this “special resonance” explanation is a common myth.

Interference and odd EM side effects

  • Examples: microwaves and fridges breaking wireless mice; 2.4 GHz Wi‑Fi beaconing holding bathroom PIR light switches “on”; power-line noise from bad relays affecting industrial machinery; office chairs and static/EM pulses blanking monitors; Wi‑Fi cards coupling into DisplayPort cables.
  • Polarization details: US FM vs TV vertical/horizontal; in Europe, mixed/circular polarization is more common, with exceptions in interference-prone areas.

Debugging folklore and pattern

  • Large portion of the thread turns into a catalog of “weird bug” stories: printers that misbehave on specific days, email that can’t travel >500 miles, cars and radio stations or ice cream, chairs turning monitors on/off, etc.
  • Many link to classic debugging tales and books, emphasizing the importance of careful observation, correlation vs causation, and considering environmental factors.

Skepticism and alternative hypotheses

  • Some think the article’s tree explanation fits; others suspect unmentioned factors like increased RF congestion, misaligned hardware, or weather-driven failover paths.
  • A few argue that an outdoor point‑to‑point bridge is such an obvious suspect that leaving it for last, while good storytelling, is unrealistic.