Peering through the clouds is an intelligence analyst’s worst nightmare – and Beijing knows it. China is actively exploiting weather conditions to move military assets and materiel during persistent cloud cover over the Taiwan Strait and China’s coastal areas.
Summer months are traditionally the time for the People’s Liberation Army (PLA) to stage amphibious exercises, with some of the largest and most complex military exercises across Fujian, Guangdong, and Zhejiang. The prevailing weather conditions during this period negatively impact Taiwan’s ability to monitor and understand PLA training progress, movement of materials, and fundamentally provide early warning to Taiwan’s leadership.
Using 2024 as a baseline, from January to June, the PLA’s key training areas were under partial or total cloud cover for 70-73 percent of the time. From an intelligence production point of view, this is challenging for most nations in the First Island Chain, as their primary sensing is electro-optical (EO). This is also the time of year the PLA conducts basic training and prepares for their large-scale amphibious exercises during the summer and fall.
Russia effectively used this tactic prior to the invasion of Ukraine. The Russian army amassed troops under the guise of their annual military exercises during the winter months where they experienced high cloud cover. While their lightning strike tactics failed to deliver a coup d’etat, they managed to catch Ukraine by surprise.
However, the Taiwan Strait experiences some degree of cloud cover between 50-80 percent of the time, this means areas of interest just across the strait are already difficult to monitor. China also needs to be able to peer through darkness and the weather, here the balance is shifting in their favor.
The PLA continues to deploy an increasing number of satellite constellations to achieve persistent, all-weather monitoring across the Indo-Pacific. China operates a constellation of dual-use EO, synthetic aperture radar (SAR), and electronic intelligence (ELINT) satellites. These constellations of satellites are increasingly automated to enable a real-time tip and cueing. The number of and capability of these satellites are allowing China to easily outpace Taiwan’s limited ISR architecture. For the PLA, this is not a technical luxury – it is a national security priority needed to overcome the United States in the event of a Taiwan contingency.
Prevailing weather conditions from January until July make it that much harder for Taiwan to maintain constant watch over the hundreds of military sites across China to provide early warning of PLA behavior. Since 2022, China has expanded the range of locations in which they practice warfare on Taiwan – from moving models of U.S. carriers on rails in the desert to helicopter cavalry practice in Zhejiang Province.
In military parlance, the Taiwan leadership needs indications and warnings to understand the PLA’s readiness to execute combined arms exercises. This means being able to maintain constant watch over hundreds of areas several times each day, from the waters around Taiwan and deep into China, where drones cannot fly. Intelligence is Taiwan’s best strategy to counter China’s tactic of choice: gray zone warfare.
To preserve early warning and strategic autonomy, Taiwan must adopt a hybrid ISR strategy built on SAR, EO, machine learning, meteorological intelligence, and deepened international cooperation. Mitigating measures must include, at a minimum, investment in ISR capability, not just munitions.
Proper intelligence production requires the complementary use of multiple sensing systems including SAR and electro-optical imaging – especially when data is shared with friends and allies. Taiwan needs to build capacity to show its commitment to self-defense to its key allies. There are no quick and easy solutions other than to co-invest in satellite constellations with like-minded states.
Without weather-resilient ISR, Taiwan will be unable to see the storm brewing just across the horizon.