--- title: "Can you fly a drone in fog? Visibility rules and risks" description: "What counts as fog, the Part 107 visibility and cloud rules, VLOS in the EU, what fog does to a drone and how to check visibility before you fly." canonical: https://droneweatherforecast.app/guides/can-you-fly-a-drone-in-fog lang: en site: Drone Weather Forecast updated: 2026-11-14 alternates: - lang: pt-BR url: https://droneweatherforecast.app/pt/guides/can-you-fly-a-drone-in-fog - lang: es url: https://droneweatherforecast.app/es/guides/can-you-fly-a-drone-in-fog html: https://droneweatherforecast.app/guides/can-you-fly-a-drone-in-fog markdown: https://droneweatherforecast.app/guides/can-you-fly-a-drone-in-fog.md llms_txt: https://droneweatherforecast.app/llms.txt --- # Can you fly a drone in fog? > What counts as fog, the Part 107 visibility and cloud rules, VLOS in the EU, what fog does to a drone and how to check visibility before you fly. *By [Renan Rafael Bertoldo](https://droneweatherforecast.app/about) · Last updated: 2026-11-14* **Short answer: in most cases, no.** Meteorologists call it fog when visibility drops below **1 km**. Part 107 in the United States requires at least **3 statute miles (about 4.8 km)** of flight visibility, so a Part 107 flight in fog needs a waiver. US recreational flyers and EU open-category pilots must keep the drone in **visual line of sight**, which is exactly what fog takes away. DJI's Mini 4 Pro manual also lists fog among the conditions not to fly in. ## What counts as fog The WMO International Cloud Atlas defines fog as tiny droplets that reduce horizontal visibility at the surface to **less than 1 km**. When visibility stays at 1 km or more, it is called **mist**. Mist can still be below the Part 107 minimum: anything under 3 statute miles is. ## Drone visibility requirements: the rules ### United States: Part 107 - **Visibility (§107.51(c)):** at least 3 statute miles, observed from the control station. The rule defines it as the average slant distance at which prominent unlighted objects can be seen and identified by day (prominent lighted objects at night). - **Low clouds (§107.51(d)):** at least **500 ft below** the cloud and **2,000 ft horizontally** from it. At the 400 ft height limit that means a cloud base of at least 900 ft above the ground. With a cloud base at 600 ft, you can climb no higher than 100 ft. - **Visual line of sight (§107.31):** the pilot or a visual observer must see the drone throughout the flight, unaided except for corrective lenses, to know where it is and watch the airspace for other aircraft. Both §107.51 and §107.31 are on the list of rules the FAA can waive (§107.205). Without a waiver, fog grounds a Part 107 flight. These figures are Part 107 rules. For **recreational flyers**, the FAA requires flying within visual line of sight so they can see other aircraft and avoid them. ### European Union: open category In the open category of Regulation (EU) 2019/947, the test is visual line of sight: - Article 4(1)(d): the remote pilot keeps the drone **in VLOS at all times**, except in follow-me mode or with an unmanned aircraft observer. - VLOS means **continuous unaided visual contact** with the drone. - UAS.OPEN.060(2)(b) adds a thorough visual scan of the surrounding airspace, and the pilot must end the flight if it puts other aircraft, people or property at risk. - UAS.OPEN.060(2)(e) says to fly **in accordance with the manufacturer's user manual, including its limitations**. When the manual says not to fly in fog, that limit applies in the open category too. Local zones and national rules come on top of this; see the [rules and no-fly zones by country](https://droneweatherforecast.app/no-fly-zones). ## What fog does to a drone - **You lose sight of it.** Fog hides the drone, and it hides any other aircraft nearby too. Losing sight of the drone is what breaks the VLOS rules above. - **Moisture.** The DJI Mini 4 Pro manual warns that flying in **heavy fog or clouds can make the gimbal wet and cause a temporary failure**, and it says not to use the aircraft in humid environments. Before take-off it asks you to wipe any water off the glass of the vision sensors. - **Vision sensors.** The manual says not to fly when visibility is **below 100 m**: a limit for the sensors, not a visibility where flying is safe or legal. It also notes that Vision Positioning and Obstacle Sensing can be temporarily turned off in clouds and fog; without them the drone holds position on satellites only, with no obstacle sensing and no automatic slowdown near the ground. - **Not the GPS.** GPS is designed as an all-weather system, so fog does not take away your satellites ([GPS satellites for drones](https://droneweatherforecast.app/guides/drone-gps-satellites)). That still does not let you fly what you cannot see. - **Cold fog.** Close to 0 °C, fog can leave ice on the propellers ([flying in cold weather](https://droneweatherforecast.app/guides/flying-a-drone-in-cold-weather)). ## Planning around fog 1. Check the **hourly visibility**, not just the daily icon. Visibility can change from one hour to the next. 2. Look at **cloud cover** in the hours you plan to fly. If you fly under Part 107, also check how low the cloud base is, because the 500 ft clearance applies to it. 3. **Judge on site.** Under Part 107 you must be able to identify prominent objects 3 statute miles away from where you stand. Anywhere, if the drone would drop out of sight at your planned distance, stay on the ground. 4. If fog moves in, **bring the drone back while you can still see it**, and dry it before you put it away. The [pre-flight checklist](https://droneweatherforecast.app/guides/drone-pre-flight-checklist) covers the rest, and wet weather is covered in [flying in the rain](https://droneweatherforecast.app/guides/can-you-fly-a-drone-in-the-rain). ## How Drone Weather Forecast checks it For every forecast hour, the app marks the hour **red** when visibility drops below your minimum. The default is **5 km**, just above the Part 107 minimum of 3 statute miles (4.8 km), and you can change it. It also shows **cloud cover** for every hour; cover is a percentage, not a height, so the Part 107 cloud clearance is yours to check. Data comes from Open-Meteo by default, with Apple WeatherKit and WeatherAPI as options. A forecast plans the day; the visibility you see on site decides it. ## Sources Checked 14 November 2026. - [WMO International Cloud Atlas: fog compared with mist](https://cloudatlas.wmo.int/en/fog-compared-with-mist.html) - 14 CFR Part 107 (eCFR): [§107.51 Operating limitations](https://www.ecfr.gov/current/title-14/section-107.51), [§107.31 Visual line of sight](https://www.ecfr.gov/current/title-14/section-107.31), [§107.205 List of regulations subject to waiver](https://www.ecfr.gov/current/title-14/section-107.205) - [FAA: Recreational flyers](https://www.faa.gov/uas/recreational_flyers) - [Commission Implementing Regulation (EU) 2019/947](https://www.legislation.gov.uk/eur/2019/947/adopted): Article 2(7), Article 4(1)(d) and UAS.OPEN.060, text as adopted - [DJI Mini 4 Pro User Manual v1.4](https://dl.djicdn.com/downloads/DJI_Mini_4_Pro/20240627/DJI_Mini_4_Pro_User_Manual-EN.pdf) - [U.S. Space Force: Global Positioning System fact sheet](https://www.ussf-cfc.spaceforce.mil/About-Us/Fact-Sheets/Display/Article/2381726/global-positioning-system) ## More guides - [Can you fly a drone in the rain?](https://droneweatherforecast.app/guides/can-you-fly-a-drone-in-the-rain) - [Flying a drone in cold weather](https://droneweatherforecast.app/guides/flying-a-drone-in-cold-weather) - [The KP index explained for drone pilots](https://droneweatherforecast.app/guides/kp-index-for-drone-pilots) - [How many satellites does a drone need?](https://droneweatherforecast.app/guides/drone-gps-satellites) - [Wind at altitude: why it is windier up there](https://droneweatherforecast.app/guides/wind-at-altitude) - [Drone pre-flight checklist](https://droneweatherforecast.app/guides/drone-pre-flight-checklist) - [UAV Forecast alternatives in 2026](https://droneweatherforecast.app/guides/uav-forecast-alternatives) - [How much wind can a drone handle?](https://droneweatherforecast.app/guides/how-much-wind-can-a-drone-handle) - [Wind vs gusts for drone pilots](https://droneweatherforecast.app/guides/wind-vs-gusts) - [Flying a drone in hot weather](https://droneweatherforecast.app/guides/flying-a-drone-in-hot-weather) - [Golden hour and blue hour calculator](https://droneweatherforecast.app/tools/golden-hour-calculator) ## Check the wind for your drone before every flight Drone Weather Forecast compares the hourly forecast, gusts, KP index and satellites with your drone model. Free on Android and iOS, no ads. - [Get it on Google Play](https://play.google.com/store/apps/details?id=xyz.droneweather.app) - [Download on the App Store](https://apps.apple.com/app/drone-weather-forecast/id6768126094)