weather balloon

American  

noun

Meteorology.

1. sounding balloon.

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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.

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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

However, there is no evidence to suggest that any of those changes directly affected weather balloon launches in the areas impacted by the floods in Texas.

From BBC • Jul. 7, 2025

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

But Project Grudge had an answer, it was a weather balloon.

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