Ward-by-ward heat risk maps that tell city heat cells where to act first
TL;DR Hotward builds ward-level heat vulnerability maps for Indian cities by joining satellite surface temperature with census and service data. Municipal corporations and state disaster authorities pay a yearly fee, and what they get is a short pre-summer list of wards that need cooling centres, water points and outreach first.
Heat already kills in India. By early June 2024, media counts put heatwave deaths at 219, and over 40,000 suspected heatstroke cases were reported that summer[1]. Cities do have plans now - a ministry reply in July 2026 said heat action plans exist for 23 states, 195 districts and 64 cities[2]. A review of eight city plans against WHO's core elements still found clear gaps[3].
The weak link is where to send help. Heat risk is not just temperature, and Jodhpur shows why. Researchers split its 80 wards into 25 high, 35 moderate and 20 low vulnerability, and found the hottest surfaces weren't always where the most at-risk people lived[4]. Most plans still treat a whole city as one unit.
Hotward produces one map and one list per city before each summer. The map scores every ward on three things - exposure (land surface temperature from free satellite passes and local weather stations), sensitivity (young children, older people, outdoor workers, slum share) and capacity to cope, which covers tree cover, health centres and water supply. A model fills gaps where ward data is missing and flags which scores rest on thin evidence.
The list is the bit officials actually use. It names the 10–15 wards where a cooling shelter, a drinking-water point or an ASHA outreach round would reach the most vulnerable people, and it updates during heatwave alerts. After each summer, Hotward checks the plan against hospital heatstroke counts where the city shares them.
To be clear, this is planning support and not a warning service. Official heat alerts stay with IMD and the disaster authority[5]. The product uses aggregated public data, so personal-data duties under the DPDP Act stay light.
The users are the heat-action-plan cell inside a municipal corporation, usually under the health or disaster wing. The payers are the corporation itself, a state disaster management authority or a philanthropy funding the city's plan. Today research partners often do this work free, or a consultant does it as a one-off study, and there's no public price list. Expect annual contracts in the low lakhs per city, bought through tenders or GeM.
City heat plans have spread fast, and the ministry is now counting them[2]. Peer-reviewed ward-level methods exist for an Indian city[4], so you can defend the approach in a council meeting. The Smart Cities Mission closed in March 2025[6], which left data cells in many cities looking for practical work.
Nobody publishes a figure for Indian spending on heat vulnerability mapping. The firmest count is the buyer pool - 64 cities and 195 districts with heat action plans[2], and each one needs a vulnerability section. As an adjacent signal, one urban-safety audit startup shows Indian city governments, including Delhi and NDMC, do pay for audit data on public spaces[7].
Research groups such as NRDC and its Indian partners have helped Ahmedabad and Jodhpur build plans and indices[4], but as grant-funded projects and not a product you can repeat. Urban-safety audit firms run city audits on safety and lighting rather than heat[7]. Global satellite analytics firms sell heat layers but not ward lists tied to Indian plan formats. So the gap is a low-cost yearly service any mid-sized city can renew.
| Difficulty | Moderate (38/100) |
| Starting capital | ₹55–95 L |
| Time to launch | 6–9 months |
The modelling is not the hard part. Getting ward boundaries, slum lists and health-centre locations out of each corporation takes months, and selling to government is slow because budgets arrive in the wrong quarter. Renewals depend on whether anyone used last summer's list.
No sector licence is needed for heat planning support. Just don't drift into issuing warnings.
Building this outside India? The categories above usually have a local equivalent, so check with your own regulator.
Don't trust AI scores where the ward data is thin, and never let the product act as a warning service. Official alerts stay with IMD.
Want to work out the AI layer for Hotward? Talk to Yash →
I think this is worth a shot if you have GIS skills and the patience for government buyers. If you need fast revenue then it's a poor fit. First prove one city will act on the list - get a municipal heat cell to place shelters or water points using your top 15 wards in a single summer.
My estimate is ₹55–95 L, mostly for GIS staff, data work and the slow first city sale. The kit breaks it down.
No sector licence, because this is planning support and not a warning service. Use aggregated data and follow NDMA heat guidance.
Yes, satellite heat data is free worldwide and many cities now run heat plans. Check who owns heat alerts locally and keep clear of that role.
The free Hotward validation kit has the line-by-line capital breakdown, the effort scoring, the data and procurement checklist, a 14-day validation sprint with pass/fail targets, a 90-day launch plan, 10 interview questions for city officials and funders, and 5 assumptions to test. Download the kit →
Thinking about building Hotward or something close to it? The make-or-break work is getting a city to act on the ward list and then pay to renew it, and I'm happy to think that through with you. If you need a hand, you know where to find me. Talk to Yash →
For illustration only. Names are fictional and ideas hypothetical; sourced facts are real but may be out of date. Nothing here is legal, financial or professional advice, and Yash Khatri is not personally liable for any use of it. Read the full disclaimer.