Sea-Tac Airport · KSEA
Seattle, Seattle-Tacoma International Airport
As of 8:05 pm · Thursday, July 30
Sunny
73.40°F
station reports whole-degree readings (±1°)
↑≈78–80°
↓55.0°
Trend
69.40°
by thu 11:05 pm
Raw local trend ±0.46°/hr
+0.12°/hr
not statistically significant right now - the error bar spans zero, so treat this as flat
Applied, after damping
80%
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
67.40°–71.40° (±4.00°)
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.
Last 6h + projection
6h ago
thu 11:05 pm
Estimated hottest/coldest time of day
↑
≈78–80°
today's high so far · est. peak ~4:15 pm
↓
55.0°
expected low tonight · est. trough ~fri 5:46 am
Actual so far today
↑
≈78–80°
recorded at 5:10 pm
station reported 26°C (whole degree), so this is ±0.9°F
↓
54.0°
recorded at 3:45 am
Yesterday
↑
75°
recorded at 2:50 pm
↓
56°
recorded at 12:25 am
final NWS climate report (CLI) - the value Kalshi settled on
Tomorrow's high
83.00°
~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
55.00°
~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
Observed high: ≈78–80°F
station reported 26°C (whole degree), so this is ±0.9°F
74° or below
75° to 76°
77° to 78°
79° to 80°
81° to 82°
83° 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-26JUL30
Kalshi · today's high market volume
139,575
contracts traded, last 24h
Dollar volume (our estimate)
≈$42,648 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
Observed low: 54.0°F
station's own 1-minute figure from the METAR remarks - not the rounded 5-minute feed
47° or below
48° to 49°
50° to 51°
52° to 53°
54° to 55°
56° or above
Trades stay manual for now - this is a side-by-side view for a human to review, not an automated signal.
KXLOWTSEA-26JUL30
Kalshi · today's low market volume
9,296
contracts traded, last 24h
Dollar volume (our estimate)
≈$3,986 est.
Kalshi · tomorrow's high market
Estimated high: 83.00°F
80° or below
81° to 82°
83° to 84°
85° to 86°
87° to 88°
89° or above
Highlighted bracket is the one this tool's tomorrow-high estimate falls into.
KXHIGHTSEA-26JUL31
Kalshi · tomorrow's high market volume
9,696
contracts traded, last 24h
Dollar volume (our estimate)
≈$2,209 est.
Kalshi · tomorrow's low market
Estimated low: 55.00°F
49° or below
50° to 51°
52° to 53°
54° to 55°
56° to 57°
58° or above
Highlighted bracket is the one this tool's tomorrow-low estimate falls into.
KXLOWTSEA-26JUL31
Kalshi · tomorrow's low market volume
1,082
contracts traded, last 24h
Dollar volume (our estimate)
≈$289 est.
Next-day forecast · track record
| Forecast for | High est. | Actual | Err | Low est. | Actual | Err |
|---|---|---|---|---|---|---|
| 07-31 | 83.0 | — | pending | 55.0 | — | pending |
| 07-30 | 76.0 | 78.8 | pending | 53.0 | 53.6 | pending |
| 07-29 | 76.0 | 75.2 | +0.8 | 55.0 | 57.2 | -2.2 |
| 07-28 | 74.0 | 73.4 | +0.6 | 59.0 | 60.8 | -1.8 |
| 07-27 | 77.0 | 78.8 | -1.8 | 57.0 | 59.0 | -2.0 |
| 07-26 | 71.0 | 73.4 | -2.4 | 60.0 | 60.1 | -0.1 |
| 07-25 | 73.0 | 73.4 | -0.4 | 58.0 | 57.2 | +0.8 |
| 07-24 | 84.0 | 82.4 | +1.6 | 60.0 | 57.0 | +3.0 |
High: MAE 1.54°F, bias +0.16°F over 8 days · Low: MAE 1.91°F, bias +0.39°F over 8 days. Bias is signed forecast minus actual, so positive means the forecast ran warm. Days still in progress show pending - they are excluded from the averages, because scoring against a partial day's high is what made these numbers look twice as bad as they are.
Weekly performance · high (7 of 7 days)
| Date | Predicted | 1h before pred. | NWS 1h before | Actual | 1h before actual | Temp Δ | Time Δ | Kalshi peak vol. | Kalshi implied |
|---|---|---|---|---|---|---|---|---|---|
| 07-29 | 4:15pm · 75.2° | 73.4° | 75.0° | 2:50pm · 75.0° | 73.4° | +0.20 | +85 min | 15,096 @ 3:45pm | 76° (76° to 77°) |
| 07-28 | 4:15pm · 73.4° | 71.6° | 73.0° | 12:07pm · 73.4° | 69.8° | +0.00 | +248 min | 6,642 @ 11:30am | 74° (74° to 75°) |
| 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°) |
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 (7 of 7 days)
| Date | Predicted | 1h before pred. | NWS 1h before | Actual | 1h before actual | Temp Δ | Time Δ | Kalshi peak vol. | Kalshi implied |
|---|---|---|---|---|---|---|---|---|---|
| 07-29 | 5:44am · 57.0° | 60.8° | 56.0° | 1:05am · 56.0° | 59.0° | +1.00 | +279 min | 1,899 @ 10:00pm | 54° (54° to 55°) |
| 07-28 | 5:42am · 60.4° | 60.8° | 60.0° | 11:55pm · 57.2° | 60.8° | +3.20 | -1093 min | 6,240 @ 8:15am | 58° (57° to 58°) |
| 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°) |
Monthly performance · July 2026
High
Temp bias (signed)-0.23°F (8 days)
Temp MAE0.40°F
NWS bias (signed)-1.20°F (7 days)
NWS MAE1.49°F
model's MAE is 1.09°F lower (better) than NWS's this month.
Peak-time bias (signed)+59 min
Peak-time MAE75 min
Mean Kalshi peak volume8,243 contracts
Model in Kalshi's top bracket100% (8 days)
Low
Temp bias (signed)+0.33°F (8 days)
Temp MAE1.23°F
NWS bias (signed)+1.30°F (6 days)
NWS MAE1.97°F
model's MAE is 0.74°F lower (better) than NWS's this month.
Peak-time bias (signed)-56 min
Peak-time MAE238 min
Mean Kalshi peak volume1,641 contracts
Model in Kalshi's top bracket62% (8 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)
Insufficient data - only 1 bet(s) so far (need at least 5 to treat win rate/band coverage as meaningful).
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)
Insufficient data - only 1 bet(s) so far (need at least 5 to treat win rate/band coverage as meaningful).
Conditions
Wind
4.60 mph
Cloud cover
0%
Pressure
rising
Trend confidence
80%
Marine push
quiet
via KHQM + KORS
Offshore flow
quiet
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
71.6°
Sunny · KBFI, 8:05 pm
Wind
5.7 mph
Today, per NWS
↑
72.0°
forecast high ~7:00 pm
↓
63.0°
forecast low ~11:00 pm
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.