Real-time KIAH station data combined with Kalshi prediction market pricing. Identify mispriced contracts around Gulf Coast tropical moisture, afternoon convection, and hurricane season volatility.
Houston sits in the humid subtropical climate zone along the Texas Gulf Coast, where warm Gulf of Mexico waters dominate precipitation patterns year-round. The city's flat topography and proximity to Galveston Bay create conditions favoring intense convective rainfall, particularly during summer months when sea breeze convergence triggers daily thunderstorms. Tropical systems from the Gulf represent the highest-impact precipitation events, with landfalling hurricanes and tropical storms capable of delivering 10-20 inches in 24-48 hour windows.
Annual precipitation at KIAH averages 53.2 inches across approximately 104 days with measurable rainfall. June ranks as the wettest month with 5.9 inches average, followed closely by May (5.2 inches) and September (4.9 inches) during peak tropical season. January through March constitute the driest period, with February averaging just 3.1 inches. The city experiences pronounced wet season intensity from April through October, when Gulf moisture transport and tropical cyclone activity combine to produce 65% of annual totals. Daily precipitation amounts exhibit high variability, with trace events common but 1+ inch days occurring 20-25 times annually.
Houston's precipitation volatility creates significant trading opportunities on Kalshi, particularly during hurricane season when tropical development windows can shift monthly totals by 300-400% from climatology. The city's position at the intersection of Gulf tropical tracks and continental frontal boundaries produces forecast uncertainty that often persists within 72-96 hours of events, creating late-window price discovery inefficiencies. Summer convective patterns generate daily probability floors around 40-50% that traders frequently misprice during early-month contracts, while winter cold front timing offers higher-confidence setups when GFS/ECMWF ensemble guidance converges 5-7 days out.
Live Kalshi odds coming soon — connect your account to see real-time markets
View Dashboard →Houston precipitation markets on Kalshi exhibit distinct seasonal liquidity patterns tied to forecast complexity. April through October contracts typically see sustained volume as tropical uncertainty keeps monthly totals wide-ranging—a single tropical system can add 8-15 inches, pushing months from below-normal to record territory. The 12z and 18z GFS runs drive the most significant price movements during active tropical periods, as convection-allowing models update their track and intensity forecasts. Traders who monitor NHC probabilistic guidance 5-7 days ahead of potential development windows gain substantial edge over those reacting to deterministic track forecasts within 72 hours.
Summer months present a distinct challenge: daily sea breeze convection creates a reliable 30-40% baseline precipitation probability, but pinpointing which days produce KIAH-measurable rain versus activity displaced 15-20 miles inland requires parsing high-resolution HRRR model output. Many traders overpay for daily contracts during July-August heat peaks, failing to account for KIAH's specific location relative to the bay breeze convergence zone. The 00z model cycle often shows organized overnight convective complexes that dissipate by morning, leading to false signals in automated trading systems.
The most common trap in Houston trading involves conflating areal coverage with station-specific measurement. Widespread stratiform rain from Gulf moisture advection reliably produces measurable precipitation at KIAH, but isolated supercells—even severe ones reported across metro Houston—frequently miss the airport observation site entirely. Traders who rely on general Houston-area radar composites without checking KIAH-specific rain gauge accumulation in CLI reports consistently lose on narrow daily contracts. Winter cold front timing offers the highest-confidence setups, as synoptic-scale systems produce more predictable coverage, though amounts remain modest and monthly threshold contracts require stacking multiple front passages.
KIAH operates an Automated Surface Observing System (ASOS) that records precipitation via heated tipping-bucket rain gauge, reporting at one-minute intervals with automated METAR issuance each hour. The official daily Climate Summary (CLI) report, issued after midnight local time, provides the 24-hour precipitation total from 00:00-23:59 UTC that Kalshi uses for contract settlement. This CLI value represents the legally binding measurement for all daily and monthly precipitation markets tied to Houston. Trace precipitation—recorded as "T" in CLI reports when moisture registers but totals less than 0.01 inches—does not qualify as measurable precipitation for Kalshi contract settlement purposes. Contracts specifying "Will Houston receive at least 0.01 inches" settle as "No" on trace days, a critical distinction during light drizzle events common with Gulf maritime stratus. Monthly contracts aggregate daily CLI totals, meaning a month with 15 trace days and 8 days with 0.01+ inch events settles based solely on the sum of those 8 measurable days. The ASOS system undergoes routine maintenance and calibration, with any equipment outages triggering manual observations from NWS staff; these manual reports carry equal weight for settlement, though outages at KIAH remain rare due to redundant systems at this major airport facility.
KIAHMarch through May brings increasing Gulf moisture and severe weather as upper-level jet stream energy interacts with returning warmth. May averages 5.2 inches with frequent heavy rainfall events from slow-moving frontal systems and early-season tropical disturbances. Tornado risk peaks in April when strong wind shear accompanies surface-based instability.
June through August features daily sea breeze convection with 40-50% baseline precipitation probability, though amounts vary widely based on storm placement relative to KIAH. July and August average 4.2-4.7 inches despite frequent activity, as most storms produce brief intense downpours rather than sustained rainfall. Heat index values consistently exceed 105°F between rain events.
September through November maintains elevated precipitation from tropical systems and early-season cold fronts. September averages 4.9 inches with highest variability—landfalling hurricanes can push monthly totals above 15 inches while quiet patterns yield under 2 inches. By November, rainfall drops to 4.1 inches as frontal passages become more frequent but tropical moisture diminishes.
December through February represents the dry season with cold fronts producing light to moderate stratiform precipitation. February averages just 3.1 inches across the driest period climatologically. Freezing precipitation remains rare but possible during strong Arctic intrusions, though most winter systems produce plain rain with 24-48 hour Gulf moisture return between fronts.
Houston receives an average of 53.2 inches of precipitation annually at KIAH, distributed across approximately 104 days with measurable rainfall. June is the wettest month at 5.9 inches average, while February is driest at 3.1 inches.
Kalshi offers daily and monthly precipitation contracts for Houston that settle based on KIAH official CLI reports. Contracts specify thresholds like "Will Houston receive at least 0.01 inches on [date]" or bracket ranges for monthly totals. Traders buy Yes or No positions, with contracts settling to $1 for the correct outcome.
June averages 5.9 inches of precipitation, making it Houston's wettest month climatologically. May (5.2 inches) and September (4.9 inches) follow closely, with September totals highly variable due to tropical cyclone activity during peak hurricane season.
No. Trace precipitation (recorded as "T" when less than 0.01 inches) does not count as measurable for Kalshi contract settlement. Only amounts of 0.01 inches or greater reported in the official KIAH CLI summary qualify as measurable precipitation.
Atlantic hurricane season runs June 1 through November 30, with Houston's highest tropical cyclone risk in August and September. Landfalling systems can produce 10-20 inches of rain in 24-48 hours, creating extreme volatility in monthly precipitation market pricing during these months.
Synoptic-scale winter systems show high skill 5-7 days out, while summer convective rainfall remains challenging beyond 48 hours due to sea breeze interaction variability. Tropical system track and intensity forecasts improve dramatically inside 72 hours, creating significant price discovery windows as NHC updates guidance.
Sea breeze convergence between Gulf onshore flow and continental heating creates a mesoscale boundary 10-30 miles inland during summer months. Daytime heating destabilizes the maritime air mass, triggering deep convection along this boundary, though specific storm locations vary daily based on subtle wind shifts.
The ECMWF and GFS ensemble means provide superior guidance for synoptic systems 5+ days out, while the HRRR convection-allowing model offers best skill for daily convective timing within 18 hours. During tropical events, HWRF and HAFS hurricane-specific models become critical for intensity and rainfall forecasts inside 72 hours.
Affiliate link · Affiliate Disclosure