2025 Karachi’s September and October Rains- A tale of Nongfa and Shakhti

‘Rivers took back what was theirs’, the tale of 2025’s Monsoon Season! In the midst of the turmoil, we seemed to have overlooked the fact that they were RIVERS…

In the past, the city of Karachi has experienced rain in September and October. Hence, it did not come as a surprise when a remnant of Nongfa set its sights on southern Pakistan in early September and then later Shakhti.

September

Let’s take a look at all the prominent September monsoon spells. The average monthly rainfall ranges from 11 mm to 30 mm, as per the GoP’s official data. However, there have been instances where the rains exceeded the normal monthly range, and Karachi witnessed torrential downpours, e.g., 2005, 2011, 2019, and most recently, 2021.

1. 2005 – What was classified as a “dry monsoon season” turned out to be only a temporary lull, as the rains came back with full force. Around 50 mm of rain in 24 hours (<80 mm in 48 hours) was recorded.
2. 2011 – No one can forget that year’s +1,000 mm of rain in the province during the monsoon season. The city recorded up to 140 mm of rain in 24 hours (official), an extreme rain event. It remains the wettest single-day rain in September to date.
3. 2019 – There were multiple spells in September. The first spell led to 40 mm of rain. Cyclone Hikaa left moisture for a low-pressure system over Gujarat-Rajasthan that caused heavy stormy rain on September 27, 2019 (>100 mm of rain, an unofficial stat) in Karachi.
4. 2021 – There were several spells. The first caused around 68 mm of rain on September 3 in the city. There were frequent rains towards the end, unofficially making it the wettest September. 2021 saw the most prolonged monsoon season due to Cyclone Shaheen.

2025

The weather system that became Nongfa near Vietnam covered a whopping 6,500 km distance, traveling from the Philippines to Pakistan. It left a mark on every region it touched. The JTWC of the U.S. Navy & India’s IMD offer differing projections. The IMD’s forecast positioned the storm significantly inland, near Karachi, while the JTWC’s model places it to the north of the city.

The remnants of Nongfa re-intensified into a tropical depression near Sindh, leading to heavy rains in the province. Nagarparkar received 164 mm (7th Sept – Official). Karachi received 130 mm (9th Sept, official stat from Surjani Town), Diplo received 110 mm (7th Sept – Official), and Hyderabad received 85 mm (9th Sept – Official).

Both the monsoons of 2024 & 2025 in Karachi ended with tropical systems: cyclone Asna in 2024 & former cyclone Nongfa in 2025. It’s almost becoming a ritual that the monsoon ends with tropical weather systems (2021 ended with cyclone Shaheen).

Later in September, would-be cyclone Shakhti led to post-monsoon rains in Karachi, recorded at 33.4 mm at Old Karachi Airport on September 30.

October

When it turned into a cyclone, it only brought 3 mm of rain to the city on October 5, which was partly due to the westerly winds. Overall, the cyclones in October had little effect on Pakistan compared to what they could have done. Onil (2004) brought 145 mm of rain to Thatta (with 26 mm at Karachi Airport on October 3), Nilofar (2014) caused light rain, Kyarr (2019) led to high tides in DHA Phase 8, and Shaheen (2021) brought 32 mm of rain at Gulshan-e-Hadeed on October 2.

Was it the first time Karachi experienced riverine flooding?

The last time parts of the city experienced riverine flooding was back in August 2013. As per the GoP, the highest 24-hour rainfall was at 132 mm in North Karachi. The rain had a wider distribution. In September 2025, Surjani Town recorded around 130 mm in 24 hours (GoP stat).

How was the overall Monsoon Performance in Sindh?

As per GoP, June exceeded the average monthly rain (+200%) in Sindh and the tilt of the monsoon trough over northern areas in Pakistan led to below-normal July rains (-32%) in the province. However, the deluge in Karachi and other coastal areas caused a slight surplus (+1%) in August. September ended with +317% above normal rains in Sindh, “ranking 8th highest,” as per GoP’s data. Interestingly, they have classified Thatta’s 110 mm of rain as the wettest day (breaking its 2011 record of 73 mm) and not Karachi’s 130 mm (Surjani Town).

Whereas Karachi experienced a monsoon season in 2025 with 304.4 mm of rainfall, surpassing the average of 155.6 mm, which was calculated using data available up to 1990-2020. Hence, an overall above-average monsoon season was projected by PWP!