Sea-Tac Airport · KSEA
Seattle, Seattle-Tacoma International Airport
As of 12:00 am · Wednesday, July 29
Clear
59.00°F
station reports whole-degree readings (±1°)
↑≈58–60°
↓56.5°
Trend
57.70°
by wed 3:00 am
Raw local trend ±1.41°/hr
-1.29°/hr
Applied, after damping
81%
How much of the raw trend the model trusts, based on proximity to sunrise/peak-heat hour and current cloud/wind. Low near those turning points, since the trend is about to reverse.
Uncertainty band
53.60°–61.80° (±8.20°)
Widens when local pressure is falling (unsettled weather approaching), and independently when the marine push or offshore flow signals below are elevated - separate from the trend confidence above.
Widened: offshore flow signal rising; noisy local trend fit.
Last 6h + projection
6h ago
wed 3:00 am
Estimated hottest/coldest time of day
↑
≈58–60°
projected for today's peak-heat hour · est. peak ~4:15 pm
↓
56.5°
today's overnight low, almost here · est. trough ~wed 5:44 am
Actual so far today
↑
≈58–60°
recorded at 12:00 am
station reported 15°C (whole degree), so this is ±0.9°F
↓
≈58–60°
recorded at 12:00 am
station reported 15°C (whole degree), so this is ±0.9°F
Yesterday
↑
≈72–74°
recorded at 12:00 pm
↓
≈56–58°
recorded at 11:55 pm
Tomorrow's high
77.00°
~5:00 pm · reference confidence 75%*
From the NWS hourly forecast (HRRR model) - real atmospheric dynamics, not this tool's own trend/persistence guess. The reference confidence % is still a placeholder, not a backtested figure - only 7 of 10 finalized next-day predictions using this source are logged so far; this will switch to a measured number once enough accumulate.
Tomorrow's low
54.00°
~6:00 am · reference confidence 75%*
From the NWS hourly forecast (HRRR model) - real atmospheric dynamics, not this tool's own trend/persistence guess. The reference confidence % is still a placeholder, not a backtested figure - only 7 of 10 finalized next-day predictions using this source are logged so far; this will switch to a measured number once enough accumulate.
Kalshi · today's high market
Estimated high: 59.00°F
73° or below
74° to 75°
76° to 77°
78° to 79°
80° to 81°
82° or above
Highlighted bracket is the one this tool's own estimate falls into - not a probability call, just a quick eyeball check against the market's pricing.
Bid/ask are the current highest buy offer and lowest sell offer for that bracket (last-price is the most recent trade, which can lag). A wide gap between them usually means a thin, less reliable market.
KXHIGHTSEA-26JUL29
Kalshi · today's high market volume
4,576
contracts traded, last 24h
Dollar volume (our estimate)
≈$1,107 est.
Contract count matches Kalshi's own "Volume" figure; the dollar amount is our own estimate (contracts × that hour's average price) since Kalshi doesn't publish a dollar total directly. Applies to all four volume charts on this page (today's/tomorrow's high/low).
Kalshi · today's low market
Estimated low: 56.50°F
49° or below
50° to 51°
52° to 53°
54° to 55°
56° to 57°
58° or above
Trades stay manual for now - this is a side-by-side view for a human to review, not an automated signal.
KXLOWTSEA-26JUL29
Kalshi · today's low market volume
3,614
contracts traded, last 24h
Dollar volume (our estimate)
≈$1,038 est.
Kalshi · tomorrow's high market
Market not open yet.
Highlighted bracket is the one this tool's tomorrow-high estimate falls into.
no open market
Kalshi · tomorrow's high market volume
—
contracts traded, last 24h
Dollar volume (our estimate)
—
Volume unavailable.
Kalshi · tomorrow's low market
Market not open yet.
Highlighted bracket is the one this tool's tomorrow-low estimate falls into.
no open market
Kalshi · tomorrow's low market volume
—
contracts traded, last 24h
Dollar volume (our estimate)
—
Volume unavailable.
Weekly performance · high (6 of 7 days)
| Date | Predicted | 1h before pred. | NWS 1h before | Actual | 1h before actual | Temp Δ | Time Δ | Kalshi peak vol. | Kalshi implied |
|---|---|---|---|---|---|---|---|---|---|
| 07-28 | no data | ||||||||
| 07-27 | 4:17pm · 78.8° | 77.0° | 76.0° | 5:05pm · 79.0° | 75.2° | -0.20 | -48 min ✓ | 4,086 @ 3:15pm | 78° (78° to 79°) |
| 07-26 | 4:17pm · 73.4° | 71.6° | 70.0° | 1:25pm · 74.0° | 71.6° | -0.60 | +172 min | 14,213 @ 4:45pm | 74° (74° to 75°) |
| 07-25 | 4:17pm · 73.4° | 69.8° | 71.0° | 4:20pm · 73.0° | 69.8° | +0.40 | -3 min ✓ | 14,255 @ 4:00pm | 72° (71° to 72°) |
| 07-24 | 4:18pm · 81.4° | 78.8° | 82.0° | 4:30pm · 82.0° | 78.8° | -0.60 | -12 min | 7,523 @ 4:30pm | 82° (82° to 83°) |
| 07-23 | 4:18pm · 76.1° | 73.4° | 77.0° | 4:12pm · 76.0° | 71.6° | +0.10 | +6 min ✓ | 6,476 @ 4:00pm | 76° (76° to 77°) |
| 07-22 | 4:19pm · 93.9° | —° | — | 3:53pm · 95.0° | 93.0° | -1.10 | +26 min | 7,163 @ 7:45pm | 94° (94° to 95°) |
Trailing 7 days, most recent first. Predictions only appear once calibration_log.py has logged them (recent addition) - actual/Kalshi columns work back further.
Weekly performance · low (6 of 7 days)
| Date | Predicted | 1h before pred. | NWS 1h before | Actual | 1h before actual | Temp Δ | Time Δ | Kalshi peak vol. | Kalshi implied |
|---|---|---|---|---|---|---|---|---|---|
| 07-28 | no data | ||||||||
| 07-27 | 5:41am · 57.8° | 59.0° | 57.0° | 1:35am · 59.0° | —° | -1.20 | +246 min | 981 @ 5:00am | 58° (57° to 58°) |
| 07-26 | 5:40am · 60.8° | 60.8° | 61.0° | 5:45am · 59.0° | 60.8° | +1.80 | -6 min ✓ | 944 @ 10:00pm | 60° (60° to 61°) |
| 07-25 | 5:39am · 57.2° | 57.2° | 59.0° | 4:47am · 57.0° | 60.8° | +0.20 | +52 min ✓ | 830 @ 5:30am | 58° (57° to 58°) |
| 07-24 | 5:38am · 57.0° | 57.2° | 60.0° | 4:53am · 57.0° | 59.0° | +0.00 | +45 min | 1,989 @ 5:00am | 56° (56° to 57°) |
| 07-23 | 5:36am · 61.0° | 61.0° | — | 3:53am · 61.0° | 62.1° | +0.00 | +103 min | 1,570 @ 4:15am | 60° (60° to 61°) |
| 07-22 | 5:35am · 62.6° | 69.1° | — | 6:53am · 65.0° | 69.1° | -2.40 | -78 min | 1,222 @ 6:30am | 67° (67° or above) |
Monthly performance · July 2026
High
Temp bias (signed)-0.33°F (6 days)
Temp MAE0.50°F
NWS bias (signed)-1.60°F (5 days)
NWS MAE2.00°F
model's MAE is 1.50°F lower (better) than NWS's this month.
Peak-time bias (signed)+23 min
Peak-time MAE44 min
Mean Kalshi peak volume7,839 contracts
Model in Kalshi's top bracket100% (6 days)
Low
Temp bias (signed)-0.27°F (6 days)
Temp MAE0.93°F
NWS bias (signed)+1.25°F (4 days)
NWS MAE2.25°F
model's MAE is 1.32°F lower (better) than NWS's this month.
Peak-time bias (signed)+60 min
Peak-time MAE88 min
Mean Kalshi peak volume1,267 contracts
Model in Kalshi's top bracket67% (6 days)
Bias/MAE use the same (predicted − actual) sign convention as the backtest above. Positive bias means the model's prediction ran warm/high or late; negative means it ran cool/low or early.
Paper trading · trailing 7 days
1hr before peak
No simulated bets placed yet in this window.
2hr before peak
No simulated bets placed yet in this window.
Simulated only - no real orders placed. A bet is logged when the model's own (backtest-calibrated) probability disagrees with Kalshi's price by at least 15 points - independently at ~1hr and ~2hr before the predicted peak, so the two lead times can be compared rather than picking one upfront. Kept separate on purpose - see the two blocks below.
Low market: always-bet-the-model vs. edge-gated
Low - edge-triggered (1hr)
No simulated bets placed yet in this window.
Low - unconditional (1hr)
No simulated bets placed yet in this window.
Low market only. "Edge-triggered" is the same 15-point-disagreement bet already counted above under "1hr before peak" (isolated here to just the low side, since the block above pools high and low together); "unconditional" instead bets every single day on whichever bracket the model's own point estimate falls into, no disagreement required. Comparing the two answers whether just following the model daily beats only betting when a real mispricing shows up. High doesn't get an unconditional mode - this comparison only applies to low.
Paper trading · July 2026
1hr before peak
No simulated bets placed yet in this window.
2hr before peak
No simulated bets placed yet in this window.
Low market: always-bet-the-model vs. edge-gated
Low - edge-triggered (1hr)
No simulated bets placed yet in this window.
Low - unconditional (1hr)
No simulated bets placed yet in this window.
Conditions
Wind
0.00 mph
Cloud cover
0%
Pressure
steady
Trend confidence
81%
Marine push
steady
via KHQM + KORS
Offshore flow
rising
via KELN
Trend confidence is how much the model trusts its own short-term extrapolation right now - not confidence in the readings above. It's deliberately low near sunrise or the day's peak-heat hour, since the trend is about to reverse there regardless of how strong it looks right before. Marine push (coastal/strait pressure gradient) and offshore flow (interior gap-wind gradient) are two distinguishable patterns behind Seattle temperature swings - the latter is the mechanism behind most real heat events, not just solar heating. Both are still first-pass signals, not yet calibrated against real outcomes (see calibration log).
Seattle (Fremont) · NWS gridpoint forecast
64.4°
Clear · KBFI, 12:10 am
Wind
3.4 mph
Today, per NWS
↑
72.0°
forecast high ~6:00 pm
↓
56.0°
forecast low ~6:00 am
A separate, closer-to-home comparison point - not part of the KSEA model above, and not blended into it. Sea-Tac Airport runs warmer than Fremont in summer (further from Lake Union/marine moderation), so treat these as two different microclimates. Current conditions are real observations from KBFI (Boeing Field, nearest full ASOS station - still ~5-6mi from Fremont). The high/low is NWS's own HRRR-based forecast for Fremont's actual coordinates, not this tool's in-house trend/gradient-network model - no backtesting or paper trading behind these numbers yet.