🇹🇭 Ban Waen, Hang Dong · Chiang Mai

Climate Analytics 📈

Retrospective statistics for 10 917 001 high-frequency climate readings · All time.

Timeframe: ⏳ Updating...

Updated 2026-09-30 06:14 UTC

Station Extremes & Records

Peak Smog 💀

498 AQI

Peak: 12.08.2026 21:24

Peak Heat 🔥

45.7 °C

17.05.2026 17:59

Record Cold 🥶

22.8 °C

12.09.2026 04:08

Lowest Pressure 🌪

964.3 hPa

19.05.2026 16:01

Average PM2.5 ⚖️

7.8 µg/m³

EPA humidity-corrected

Humidity 💧

23.0–100.0 %

From dry smog to tropical downpour

Max Pressure 🔼

980.4 hPa

Elevation ~300m above sea level

Total Readings 📡

10 917 001

Recorded by telemetry

🌡️ Thermal Comfort & Microclimate Analytics

Magnus-Tetens & NOAA Equations

Dew Point (Avg) 💦

24.0 °C

Severe tropical mugginess (sweat cannot evaporate)

Heat Index at Mean Conditions ☀️

34.2 °C

Extreme Caution · Sunstroke, muscle cramps, and heat exhaustion possible · from period-average T/RH

Saturation Margin 💧

Δ 5.4 °C

Dry Margin · based on period-average

Daily Temp Swing 🔄

Δ 7.7 °C

Mean 24h day-to-night variation

📅 Monthly PM2.5 Progression

µg/m³

Hourly-weighted monthly means of EPA humidity-corrected PM2.5 for the selected timeframe.

⏰ Diurnal Cycle (24h, UTC+7)

Asia/Bangkok

Averaged 24-hour PM2.5 patterns: morning boundary layer transition (06:00–09:00), midday dispersion (12:00–17:00), and evening concentration rise (18:00–21:00).

Profile Peak (Mean Max)

21.3 µg/m³

at 06:00 · mean across 173 days

Profile Low (Mean Min)

12.4 µg/m³

at 16:00 · mean across 175 days

⚡ Profile Swing

Δ 8.9 µg/m³

-42% 24h variation

06:00–09:00 Inversion

12:00–17:00 Solar Clearing

18:00–21:00 Evening Smog

Corrected PM2.5 (EPA)

🍃

Boundary-Layer Ventilation & Golden Window

Convective Flushing Kinetics

Nocturnal surface inversion breakdown, particulate clearance half-life (t½), and optimal aeration window.

✨ Bangkok Regime: Golden Ventilation Window

Golden Ventilation Window ✨

13:00 – 18:00

Duration 6h · Deep mixed layer

Avg 13.5 µg/m³ (-36.6% vs peak)

Apparent Half-Life (t½) ⏱️

12.8h

Apparent decay rate k = 0.054 h⁻¹

Morning peak to midday flush speed

Peak → Midday Flush ⚡

21.3 → 12.4 µg/m³

Peak 06:00 · Trough 16:00

Δ 8.9 µg/m³ diurnal dispersion

Nocturnal Buildup Slope 🌫️

+0.45 µg/m³/h

00:00–06:00 surface stagnation

Radiative inversion intensity

Diurnal Atmospheric Regimes Current Phase: Golden Ventilation Window

00:00 – 06:00

Inversion Trap

06:00 – 10:00

Morning Peak

10:00 – 13:00

Convective Flush

13:00 – 18:00

Golden Window

18:00 – 24:00

Boundary Collapse

🗺️ Hovmöller Space-Time Diagram · Diurnal vs Seasonal Dispersion

Each row represents one calendar day (00:00 to 23:00 UTC+7). Visualizes persistent morning inversion traps in dry season vs continuous convective cleansing in monsoon.

Good

Mod

USG

Unhealthy

Very

Haz

🌊

Atmospheric Semidiurnal Tide (S₂) & Convective Outflow Signatures

Thermal Baric Resonance

Solar thermal tidal decomposition (S₁ 24h + S₂ 12h) and candidate convective cold-pool outflow signatures with aerosol washout kinetics.

⏱️ Bangkok Solar Resonance

S₂ Semidiurnal Amplitude 🌊

1.43 hPa

Peaks: 09:52 & 21:52

Swing: ±1.43 hPa · R² (diurnal mean): 0.997

S₁ Diurnal Amplitude ☀️

1.24 hPa

Baseline P₀: 972.24 hPa

Observed: 24 / 24 hours

Candidate Outflow Signatures ⚡

0 events

Rate ≥ 0.08 hPa/min · ΔT ≤ -1.5°C

ΔRH ≥ +10% · 60m cooldown

Mean Aerosol Washout 🌧️

—

No washout events in period

PMS5003 humidity-adjusted

Barometric Tidal Harmonics S₁ + S₂ 24-Hour Diurnal Fit

Observed Model (S₁+S₂) Pure S₂

Bangkok atmospheric solar tide: S₂ resonance produces semidiurnal baric peaks at morning and evening. Removing this harmonic isolates true synoptic barometric pressure anomalies.

Convective Outflow Signatures Top Events

0 recorded

🌦️ No candidate convective outflow signatures detected in this timeframe. Requires simultaneous baric surge (≥0.08 hPa/min), rapid thermal plunge (ΔT ≤ -1.5°C), and humidity spike (ΔRH ≥ +10%).

⚖️

Weather-Matched Seasonal PM₂.₅ Contrast

Counterfactual Stratification

Burning season (March–May) vs wet-season baseline (June–September) standardized under overlapping observed weather conditions.

⚖️ Restricted Weather-Matched Contrast

ℹ️

Estimand & Methodological Scope: Observational counterfactual contrast standardizing on Bangkok local hour, weekend/weekday, ambient temperature (2°C bins), relative humidity (10% bins), and 3-hour barometric trend. Precipitation and wind transport remain unmeasured at node. Matched contrast estimated strictly for the subset of burning-season hours inside observed common support; not extrapolatable to non-overlapping heat extremes.

Matched Seasonal Contrast ⚖️

+1.7 µg/m³

+26.8% vs wet baseline CI: [-21.1%, +120.7%] · Inconclusive

95% CI: [-1.5, +7.4] · Inconclusive

Raw Seasonal Difference 📊

+6.7 µg/m³

BS 12.2 vs WS 5.5 µg/m³

95% CI: [+1.3, +11.6]

Pooled vs Stratified Gap 📉

-0.5 µg/m³

Pooled-vs-Stratified Estimator Difference

Aggregation sensitivity: pooled support medians (+1.2) vs BS-weighted contrast (+1.7)

Common Support Coverage 🎯

15.7% Limited Support

112 / 715 BS hours matched

33 strata · WS reuse 11.6x

Diurnal Dumbbell Contrast Plot (00:00 – 23:00) Hour-by-Hour Matched Separation

Burning Season Median

Matched Wet Baseline

Hours with dashed links have fewer than 10 matched samples and should be interpreted with caution. Node local time (UTC+7)

Strata Resolution & Threshold Sensitivity (Estimand Stability Check)

Multi-Grid & Cell-N Robustness

Strict (1°C / 5% RH, n≥3) 0.8% cov

+0.1 µg/m³

2 common strata

BASELINE

Standard (2°C / 10% RH, n≥3) 15.7% cov

+1.7 µg/m³

33 common strata · 112 BS hrs

Relaxed (3°C / 15% RH, n≥3) 28.0% cov

+4.7 µg/m³

51 common strata

Standard Grid (n≥5) 2.2% cov

+2.8 µg/m³

3 common strata

Dominant Matching Weather Strata Top Strata by Burning Season Weight

Hour	Temperature	Humidity	Day	Baric Trend	BS n	WS n	BS PM₂.₅	WS PM₂.₅	Δ PM₂.₅
15:00	32°C to 34°C	50% to 60%	Weekday	falling	6	18	7.2	5.7	+1.5
11:00	32°C to 34°C	50% to 60%	Weekday	falling	5	9	11.3	5.6	+5.7
14:00	34°C to 36°C	40% to 50%	Weekday	falling	5	6	10.2	8.8	+1.4
07:00	28°C to 30°C	60% to 70%	Weekday	rising	4	4	15.5	8.7	+6.8
16:00	32°C to 34°C	50% to 60%	Weekday	falling	4	19	8.4	5.5	+2.9

🌀

Monsoon Thermodynamic Phase Portrait & Onset Detector

q × θ Trajectory · Bolton (1980)

Continuous air mass trajectory in specific humidity (q) and potential temperature (θ) phase space revealing the Southwest Monsoon onset.

🧭 Surface Regime Diagnostic

ℹ️

Thermodynamic Formulation & Observational Constraints: Specific humidity (q) and potential temperature (θ) are calculated per hourly bucket using the Bolton (1980) / Magnus-Tetens formulation prior to daily median aggregation. Days with < 12 valid hours are rejected. Observational gaps > 1 day cleanly partition the phase trajectory into disconnected segments rather than drawing unphysical interpolated lines. Surface regime labels (cT-like / mE-like) indicate thermodynamic surface proxy states and do not imply synoptic upper-air or wind-vector sounding measurements.

Current Surface Regime 🧭

Humid Monsoon-like

Surface thermodynamic state consistent with mE-like Southwest Monsoon

q = 20.16 g/kg · θ = 300.07 K

Latest: 2026-09-30

Monsoon Onset Date 🌊

2026-05-21

Candidate: 2026-05-17

✓ 5/7-day persistence satisfied (q ≥ 16 g/kg)

Retreat: Not yet observed (monsoon active)

Thermodynamic Shift 🌡️

+5.3 g/kg

Δθ: -1.56 K

95% CI: [+4.62, +6.0]

5-day moving block bootstrap (1 000 iter)

Moisture Capacity 💧

22.05 g/kg (p95)

Post-onset mean q: 19.39 g/kg

p05: 14.68 g/kg · Dynamic range: 7.4 g/kg

150 valid days (≥12h/day)

📈 Thermodynamic Phase Portrait: q vs θ

Daily medians. Solid lines represent contiguous observed days; gaps > 1 day remain unbridged.

Apr May Jun Jul Aug Sep

🌦️ Monsoon Breaks & Dry Spells Post-Onset Stability

✓ No sustained monsoon breaks detected (≥ 3 consecutive days q < 16.0 g/kg). The Southwest Monsoon air mass flow remained persistent.

A monsoon break requires at least 3 consecutive valid days with q < 16.0 g/kg following confirmed onset.

🧪 Onset Threshold Sensitivity Parameter Robustness

Criterion	Candidate	Confirmed	Δq Shift
q ≥ 14 g/kg	2026-05-17	2026-05-21	+4.11
q ≥ 16 g/kg (Baseline)	2026-05-17	2026-05-21	+4.11
q ≥ 18 g/kg	2026-06-05	2026-06-09	+2.7
Hours gate: ≥ 6h vs ≥ 12h	2026-05-13	2026-05-17	+4.73

Evaluating onset detection sensitivity across moist threshold definitions and daily hour criteria.

🌈 Air Quality Distribution (US EPA)

Percentage of observed hours across standard EPA AQI tiers for the selected period.

Good (0-50)

59.68%

Moderate (51-100)

27.78%

Sensitive Groups (101-150)

3.85%

Unhealthy (151-200)

7.39%

Very Unhealthy (201-300)

1.15%

Hazardous (301+)

0.14%

🫁

Smog Episode Anatomy & Cumulative Exposure

EPA-style NowCast · Sensor-derived

Adaptive 12h-weighted NowCast smoothing, multi-hour continuous smog traps (AQI ≥ 101), and cumulative PM2.5 exposure integral. (Latest: 30.09.2026 13:00)

Safe at Period End

Cumulative PM2.5 Exposure 🫁

71 362 µg·h/m³

Time-integrated PM2.5 exposure

Hourly WHO Ref Exceedance ⚠️

37 562 µg·h/m³

Integrated concentration-time above 15 µg/m³ reference (sensor proxy, not clinical dose)

Smog Hours (AQI ≥ 101) ⏳

530h (12.7% of observed)

Total 18 continuous events

Longest Smog Siege 🌫️

6d 18h

Unbroken hazardous air stagnation

🔥 Severe Multi-Hour Smog Episodes (Ranked by Hourly WHO Exceedance)

WHO 24h Guideline: 15.0 µg/m³

#	Timeframe (UTC+7)	Duration	Peak NowCast	Cumulative Exposure	Hourly WHO Exceedance	Clearance Time
1	31.03.2026 23:00 to 07.04.2026 16:00	6d 18h	372.3 µg/m³ AQI 427 Peak at 01.04.2026 01:00	16 358 µg·h/m³	+13 928 µg·h/m³	160h to safe
2	15.04.2026 20:00 to 19.04.2026 11:00	3d 16h	110.6 µg/m³ AQI 190 Peak at 17.04.2026 12:00	5 903 µg·h/m³	+4 583 µg·h/m³	Unknown (data gap)
3	12.04.2026 12:00 to 14.04.2026 13:00	2d 2h	134.2 µg/m³ AQI 210 Peak at 13.04.2026 05:00	3 941 µg·h/m³	+3 191 µg·h/m³	Unknown (data gap)
4	31.03.2026 01:00 to 31.03.2026 14:00	14h	271.0 µg/m³ AQI 346 Peak at 31.03.2026 01:00	2 504 µg·h/m³	+2 294 µg·h/m³	Unknown (data gap)
5	19.04.2026 18:00 to 21.04.2026 17:00	2d	77.5 µg/m³ AQI 166 Peak at 21.04.2026 07:00	2 641 µg·h/m³	+1 921 µg·h/m³	11h to safe

💀 Top 5 Worst Smog Days · All time

Date	Avg PM2.5	Max AQI	Temperature	Humidity
2026-04-01	132.1	484	30.7°C	42.1%
2026-04-04	125.2	275	31.0°C	44.2%
2026-04-03	102.6	269	30.5°C	39.4%
2026-04-05	94.5	259	32.2°C	44.2%
2026-04-02	90.4	223	30.4°C	41.3%

🌿 Top 5 Cleanest Days · All time

Date	Avg PM2.5	Max AQI	Temperature	Humidity
2026-09-28	0.8	105	26.1°C	91.0%
2026-09-21	1.0	51	28.3°C	84.5%
2026-08-10	1.6	84	28.4°C	86.7%
2026-07-04	1.7	170	29.3°C	70.7%
2026-08-21	1.8	68	27.5°C	93.7%