Every monsoon, hospitals across India witness a familiar trend. A plate of pani puri on one day is followed by fever a couple of days later, and by the weekend, many patients are undergoing tests for stomach infections. In most cases, it isn't just one unhealthy meal responsible—it's the cumulative effect of consuming contaminated food and water during the rainy season.
According to the Ministry of Health and Family Welfare, nearly 70% of disease outbreaks reported in India are waterborne, with illnesses such as cholera, typhoid, hepatitis A, and diarrhoea becoming significantly more common during the monsoon. Multi-centre clinical studies also estimate India's typhoid incidence at 377 cases per 100,000 person-years, with children and adolescents being the most affected. This makes avoiding certain foods during the rainy season more than just a traditional precaution—it's an important food safety measure.
# Leafy Green VegetablesLeafy vegetables such as spinach, cabbage, lettuce, and coriander grow close to the ground, making them especially vulnerable to contamination during heavy rains. Floodwater and waterlogged fields often expose these vegetables to harmful bacteria.
A peer-reviewed Indian study analysing raw salad vegetables found that every sample contained coliform bacteria, while spinach recorded the highest bacterial contamination. E. coli was detected in nearly one out of every six samples. Another study from Dehradun observed that bacterial contamination, including Salmonella, increased significantly during the rainy season because of higher humidity and warmer temperatures.
Although washing vegetables helps reduce contamination, thorough cooking remains the most effective way to eliminate harmful microbes.
# Street Food: Pani Puri, Chaat and Bhel PuriStreet foods are among the biggest monsoon favourites, but they also carry one of the highest risks.
Many roadside vendors use water to prepare flavoured pani, chutneys and garnishes. During monsoon, municipal water supplies are more likely to become contaminated due to sewage overflow and flooding, increasing the chances of foodborne infections.
Researchers have linked this contamination to seasonal spikes in cholera and typhoid. In one notable instance, a Kolkata hospital recorded over 3,000 diarrhoea-related admissions during just a two-week monsoon period in 2015—more than twice its usual caseload.
If the food stall is surrounded by stagnant water or poor sanitation, the risk increases considerably.
# Seafood and ShellfishSeafood becomes riskier during the rainy season because heavy rainfall increases sewage contamination in rivers and coastal waters where fish and shellfish are harvested.
Studies from Indian coastal markets have found high levels of Vibrio bacteria in seafood. One Kerala-based study detected these bacteria in over 86% of tested seafood samples, with some strains carrying genes associated with severe illness.
Monsoon also coincides with the breeding season for many fish and prawn species, making fresh supply less reliable. Choosing freshly sourced, thoroughly cooked seafood—or temporarily opting for other protein sources—can significantly reduce the risk.
# Raw Salads and Cut FruitsRaw fruits and vegetables can easily become breeding grounds for bacteria during humid weather, especially once they have been peeled or sliced.
Research has shown that produce with rough surfaces and larger exposed areas accumulates microbial contamination more quickly. Fruits and vegetables displayed uncovered at roadside stalls are particularly vulnerable after prolonged exposure to heat and moisture.
Lightly steaming vegetables offers a safer alternative while preserving most of their nutritional value.
# Curd and MilkHigh humidity accelerates bacterial growth, making milk and dairy products spoil much faster during monsoon, especially when they are not refrigerated.
Traditional Indian dietary practices have long advised limiting curd consumption during certain monsoon months. Modern food microbiology supports this advice, explaining that warm, moist conditions encourage rapid bacterial multiplication.
Boiling milk thoroughly and refrigerating curd can greatly reduce the chances of contamination.
# Fried and Oily FoodsWhile there is limited scientific evidence suggesting that humidity changes how our bodies digest fried foods, food safety experts are more concerned about the repeated reuse of cooking oil.
The Food Safety and Standards Authority of India (FSSAI) has warned that reheating cooking oil multiple times can produce harmful chemical compounds. Roadside snacks like pakoras, samosas and bhajiyas are often prepared in oil that has been reused throughout the day, increasing potential health risks.
# Roadside Juices and Ice-Based DrinksFresh fruit juices, gola, kulfi and other chilled beverages may seem refreshing during humid weather, but they can expose you to contaminated water.
Many roadside vendors use untreated water or ice made from unpurified sources. Combined with freshly cut fruit that may not have been washed properly, these drinks become a common source of diarrhoea, hepatitis A and other waterborne illnesses during monsoon.
Whenever possible, choose freshly prepared beverages made with purified water or consume packaged alternatives.
# MushroomsThe rainy season provides ideal conditions for fungal growth, making wild mushrooms particularly risky.
Poison control experts and toxicology studies in India regularly report cases of mushroom poisoning during monsoon, largely due to accidental consumption of toxic wild varieties that closely resemble edible mushrooms.
Unless mushrooms are sourced from reliable commercial suppliers and stored properly, it is safer to avoid them during the rainy season.