weather balloon

American  

noun

Meteorology.

1. sounding balloon.

---

weather balloon Scientific  

1. A balloon used to carry instruments aloft to gather meteorological data in the atmosphere. Weather balloons are tracked by radar, Global Positioning System, or theodolites. The balloon itself usually contains devices to measure temperature, pressure and humidity, although it can contain specialized devices to measure the ozone in the ozone layer. Filled with hydrogen or helium gas, weather balloons can reach 35 km (22 mi) in altitude before disintegrating due to the decreased pressure of the lower stratosphere.

---

Etymology

Origin of weather balloon

First recorded in 1935–40

Example Sentences

Soon after, twitchy soldiers defending Los Angeles unleashed a barrage of antiaircraft fire at what was later suspected to be a stray weather balloon.

From The Wall Street Journal • Mar. 13, 2026

China claimed the aircraft was a weather balloon that had been blown off-course, but the U.S. said it was carrying sophisticated intelligence-gathering technology.

From Seattle Times • Jan. 9, 2024

Chinese embassy spokesperson Liu Pengyu told the outlet that the craft was a weather balloon that had flown off-course.

From Washington Times • Dec. 30, 2023

If you sent up a weather balloon first thing in the morning, it might encounter warmer air just above Earth’s surface before detecting progressively cooler temperatures as it rises higher.

From Los Angeles Times • Aug. 1, 2023

Some of the people who were watching thought that the UFO might be a lighted balloon; so, for the sake of comparison, a lighted weather balloon was released.

From The Report on Unidentified Flying Objects by Ruppelt, Edward J.