Every 2 minutes Window reads NEA's lightning detectors, rain radar and rain gauges around Bukit Timah. It tells you when a thunderstorm is closing in and roughly when it will arrive, when to stay indoors because lightning is within 10 km, and when rain is likely in the next two hours.
Haze for Bukit Timah comes from NEA's South region monitors (24-hour PSI and 1-hour PM2.5). The nearest rain gauges are Coronation Road (1.2 km) and Holland Grove Road (1.3 km).
Alerts for Bukit Timah on Telegram: @WindowSingaporeBot. A heads-up before storms and when haze turns unhealthy; nothing for maybes.