The impact of weather on rat populations and infestations

Weather’s effect on rat populations and infestations is often underestimated, yet its importance cannot be understated. Understanding how rodents and bugs respond to different environments can help predict pest problems and take preventive steps accordingly.

Climate change has already rendered cities into ideal rat breeding grounds, as warm winters and warmer summers create conditions conducive to these pests’ reproduction. Unfortunately, as our climate warms further these conditions will only worsen further.

Climate Change

As cities across the world seek to control rat populations, scientists have discovered that climate change may be providing them with ideal breeding grounds. Warmer winters and hotter summers create ideal conditions for rats to multiply at alarming rates.

Rodents serve as hosts for ticks and fleas that spread diseases, while acting as reservoirs for plague bacterium. This proliferation of creatures poses health concerns.

Recent research published in the Journal of Urban Ecology revealed that rodent-related risks have increased due to human urbanization, climate change and lack of efforts made against rats.

New York City has experienced such an extensive rat problem that Mayor Bill de Blasio pledged $32 million last year to combat them. Scientists were hired to study breeding patterns while exterminators are using dry ice and other methods to eliminate rats in their burrows.


Rat populations usually increase during warmer weather. When conditions allow rats to breed successfully, multiple litters (usually five to 10) can be produced annually.

Rats thrive on food scraps left behind by humans, particularly in neighborhoods clogged with trash. This includes leftover food from restaurants and businesses as well as trash bags and cans in yards as well as refuse disposal/transfer stations.

As temperatures decrease, rodents seek shelter from the elements by seeking out holes and crannies, tall grasses and weeds, fences, walls or rubbish piles for protection.

Because winter temperatures require lots of energy to survive, rats require plenty of food and water resources in order to stay warm – thus necessitating constant foraging for these resources wherever they may be available.


Spring marks the transitional season between winter and summer in both hemispheres, when temperatures gradually rise across both areas. In the Northern Hemisphere, it begins with vernal equinox when day and night length are roughly equal, lasting through to June or December when summer solstice occurs.

Weather plays a key role in rat populations and outbreaks. High rainfall years are often associated with rodent infestation in nonirrigated cereal production areas of Southeast Australia.

Climate variations are intricately linked with rat population dynamics, but one likely element is enhanced food resources. Climate change could play a part here by altering rainfall amounts or other abiotic conditions that encourage rodents to forage and breed.

Rats, like other mammals, rely heavily on diet to limit reproductive output. This is particularly important when considering herbivorous mammals like rats and mice which typically rely heavily on their source of food to survive.


Rats and mice inhabit different environments throughout the year, with weather having an enormous effect on their numbers. Winter brings snowy conditions with cold temperatures; spring sees rain that brings vegetation growth; summer heat is intense while fall brings cooler temperatures with less rodents around to breed;

An exceptionally wet spring and summer can exacerbate a city’s rat problem by increasing weeds, water sources, natural food sources (seeds and insects) in otherwise dry areas.

Rats often collect and consume waste during this increased activity period. As such, wet spring and summer days tend to see an increase in trash litter accumulation.

However, warmer temperatures can also bring floods that make disposing of trash more challenging for individuals.