FluCast

Historical Analysis

Multi-season ILI trends & environmental drivers

CDC LIVE
2026-W21

Multi-Year Seasonal Curve

2022 – 2026 overlay

20222023202420252026

Outbreak Heatmap

Weeks ≥ 4.5% ILI (outbreak threshold)

2022
2023
2024
2025
2026
W1W26W52

Temperature vs ILI

Inverse correlation across all seasons

Precipitation vs ILI

Environmental Correlation Summary

  • • Lower temperatures align with higher ILI activity (r ≈ −0.62).
  • • Precipitation shows weak correlation with ILI spread (r ≈ +0.14).
  • • Seasonal patterns dominate variance — sin/cos week encoding captures ~71% of signal.