Forecast accuracy

Every hour we store forecasts for 121 Seoul areas and compare them with Seoul's actual values when that hour arrives. ‘Level match’ is the share of correct five-level predictions; ‘mean error’ is the score difference on a 0–100 scale.

Last 7 days

Method currently used for 24-hour-ahead forecasts (tomorrow/weekend scores in quiet routes): Baseline · current value carried 24 h ahead. A baseline or blend replaces the pattern forecast only when it beats it on both level match and mean error over the last 7 days (at least 3,000 comparisons).

The learned model is a formula over the current value, last week's same hour (averaged with the hours either side), the 4-week median, whether weekday↔weekend changes and whether it is night. Every hour, when the actual value arrives, it nudges the formula's weights by how wrong it was (slowly forgetting old results) and corrects each area's leftover bias. The ensemble remembers each baseline's recent error per area and leans on whichever has been right. The short-term blend removes each area's usual over/under-estimate from Seoul's official forecast and mixes it with the current value by their recent errors. The day-type median uses, for weekdays, the middle value of the same hour on the weekdays of the past 2–7 days (plus the current value when today is a weekday); for weekends and public holidays, the same weekday and hour last week (the latest Sunday for a weekday holiday). The ensemble, learned model and day-type median are used for tomorrow/weekend forecasts only when they beat every baseline and blend on both level match and mean error.

DateSeoul official forecast · 1 h aheadBaseline · current value carried 1 h aheadCrowdView short-term blend · 1 h ahead (current value + bias-corrected official forecast)Seoul official forecast · 3 h aheadBaseline · current value carried 3 h aheadCrowdView short-term blend · 3 h ahead (current value + bias-corrected official forecast)CrowdView pattern forecast · 24 h aheadBaseline · current value carried 24 h aheadBaseline · median of the same weekday and hour, last 4 weeksBaseline · same weekday and hour last weekCrowdView blend · current value if tomorrow is the same kind of day, last week's same hour when weekday↔weekend changesCrowdView day-type median · weekdays: median of recent weekdays at the same hour; days off: same weekday and hour last weekCrowdView ensemble · per area, more weight on the baselines that have been right latelyCrowdView learned model · corrects itself every hour from actual results
2026-11-0266% · 9.0pt · 2420 · ±1 93%82% · 4.9pt · 2420 · ±1 96%81% · 4.7pt · 2420 · ±1 97%67% · 8.6pt · 2420 · ±1 93%75% · 7.1pt · 2420 · ±1 93%76% · 6.3pt · 2420 · ±1 96%16% · 30.2pt · 2360 · ±1 68%69% · 10.4pt · 2420 · ±1 87%–88% · 2.8pt · 2420 · ±1 99%88% · 2.8pt · 2420 · ±1 99%–81% · 4.6pt · 2420 · ±1 97%80% · 4.7pt · 2420 · ±1 98%
2026-11-0178% · 5.6pt · 2904 · ±1 97%90% · 2.6pt · 2904 · ±1 98%90% · 2.5pt · 2904 · ±1 98%76% · 6.6pt · 2904 · ±1 95%85% · 4.7pt · 2662 · ±1 95%85% · 4.3pt · 2662 · ±1 96%27% · 19.5pt · 2832 · ±1 90%75% · 8.5pt · 2904 · ±1 89%–93% · 2.1pt · 484 · ±1 98%67% · 12.5pt · 484 · ±1 83%–92% · 2.6pt · 121 · ±1 97%98% · 0.5pt · 121 · ±1 99%
2026-10-3168% · 8.5pt · 2904––68% · 8.6pt · 2904––28% · 18.0pt · 283267% · 9.7pt · 2904––––––
2026-10-3064% · 9.5pt · 2904––64% · 9.5pt · 2904––29% · 18.4pt · 283280% · 4.9pt · 2904––––––
2026-10-2964% · 9.4pt · 2904––64% · 9.6pt · 2904––31% · 18.0pt · 283284% · 3.9pt · 2904––––––
2026-10-2864% · 9.3pt · 2904––65% · 9.3pt · 2904––32% · 18.7pt · 283283% · 4.4pt · 2904––––––
2026-10-2771% · 7.6pt · 2904––71% · 7.8pt · 2904––27% · 21.3pt · 283286% · 3.3pt · 2904––––––
2026-10-2665% · 9.0pt · 2904––64% · 9.7pt · 2904––17% · 30.7pt · 283272% · 8.5pt · 2904––––––
2026-10-2566% · 9.2pt · 2904––66% · 9.3pt · 2904––28% · 18.2pt · 283276% · 6.4pt · 2904––––––
2026-10-2460% · 10.7pt · 2890––61% · 10.8pt · 2892––25% · 18.9pt · 283269% · 8.6pt · 2904––––––
2026-10-2358% · 11.5pt · 2890––59% · 11.2pt · 2898––29% · 18.6pt · 283279% · 5.7pt · 2904––––––
2026-10-2262% · 10.0pt · 2876––64% · 9.9pt · 2892––29% · 18.9pt · 283279% · 5.5pt · 605––––––
2026-10-2161% · 11.0pt · 2880––61% · 10.9pt · 2898––29% · 19.9pt · 2832–––––––
2026-10-2063% · 10.0pt · 2904––62% · 10.4pt · 2904––29% · 20.7pt · 2829–––––––

CrowdView model vs. measured, by place (last 7 days)

Where live measurements exist (Seoul areas, theme park waits, airports), every hour we compare what the model alone would have said with the actual value, learn the gap by weekday/weekend × hour, and correct the forecast. Places of the same kind without live data get half of that correction.

PlaceError beforeError afterModel biasComparisons
爱宝乐园18.0pt14.7pt-9.5pt87
仁川机场 T1航站楼18.9pt18.9pt-9.1pt165
仁川机场 T2航站楼18.1pt18.1pt-11.2pt165
金浦机场 国内航线15.5pt15.5pt-6.8pt79
济州国际机场13.6pt13.6pt-4.1pt81
金海机场 国内航线15.6pt15.6pt+15.0pt80
首尔世界烟花节11.2pt9.1pt+10.8pt69
韩国乐高乐园25.9pt20.2pt-12.9pt54
加勒比海湾水上乐园14.9pt11.0pt-13.2pt36
How it is calculated ›