# `cowin` — auto-generated data guide

> Auto-generated on 2026-10-08T15:45:30+08:00 by `scripts/generate_processed_readmes.py` from the files actually present in this directory. Do not edit by hand — re-run the generator (or `scripts/flatten_hko_data.py`) after the data changes.

## Overview

- **Files:** 3
- **Total rows:** 576,471
- **Total size:** 2292.6 KB
- **Sources:** hk_cowin
- **Time coverage:** 2023-01-01 00:00:00 .. 2025-12-31 23:00:00
- **Join keys:** use `station_id` / `station_code` to join to the station metadata table in this or the `hko` section; use the time column shown per file for temporal joins.

## Files

### `cowin_hourly_rainfall.parquet`

- **Format:** parquet · **Rows:** 549,702 · **Columns:** 6 · **Size:** 373.0 KB
- **Purpose:** HKU CoWIN QC hourly rainfall
- **Source:** hk_cowin
- **Time coverage (`obs_time_hkt`):** 2023-01-01 00:00:00 .. 2025-12-31 23:00:00
- **station_id:** 40 distinct

| Column | Type | Non-null | Range / values | Description |
|---|---|---|---|---|
| `obs_time_hkt` | str | 549702/549702 (100%) | 2023-01-01 00:00:00 .. 2025-12-31 23:00:00 | observation time (end of the 1-hour rainfall window) |
| `station_id` | str | 549702/549702 (100%) | 40 distinct; e.g. "6003" | AWS/CoWIN station identifier |
| `rain_mm_1h` | float64 | 549698/549702 (100%) | range 0 .. 249.5 | rainfall in the past hour (mm) |
| `qcscore` | str | 549702/549702 (100%) | values: G, M, F, X | CoWIN quality-control flag (G = good; M/F/X = flagged) |
| `year` | int64 | 549702/549702 (100%) | range 2023 .. 2025 | year |
| `source` | str | 549702/549702 (100%) | values: hk_cowin | source dataset identifier |

### `cowin_labels_rainstorm_hourly.csv`

- **Format:** CSV · **Rows:** 26,295 · **Columns:** 8 · **Size:** 1899.7 KB
- **Purpose:** CoWIN-based rainstorm-hour labels
- **Time coverage (`hour_end_hkt`):** 2023-01-01 00:00:00 .. 2025-12-31 23:00:00

| Column | Type | Non-null | Range / values | Description |
|---|---|---|---|---|
| `hour_end_hkt` | str | 26295/26295 (100%) | 2023-01-01 00:00:00 .. 2025-12-31 23:00:00 | hour-ending timestamp (HKT) |
| `any_station_amber` | bool | 26295/26295 (100%) | True / False | TRUE if any CoWIN station (QC=G) reached 30 mm/h |
| `any_station_red` | bool | 26295/26295 (100%) | True / False | TRUE if any CoWIN station (QC=G) reached 50 mm/h |
| `any_station_black` | bool | 26295/26295 (100%) | True / False | TRUE if any CoWIN station (QC=G) reached 70 mm/h |
| `n_amber` | int64 | 26295/26295 (100%) | range 0 .. 14 | number of stations reaching 30 mm/h |
| `n_red` | int64 | 26295/26295 (100%) | range 0 .. 8 | number of stations reaching 50 mm/h |
| `n_black` | int64 | 26295/26295 (100%) | range 0 .. 5 | number of stations reaching 70 mm/h |
| `label_basis` | str | 26295/26295 (100%) | values: any_cowin_station_qc_G | rule used to build the label (e.g. any_cowin_station_qc_G) |

### `cowin_stations.parquet`

- **Format:** parquet · **Rows:** 474 · **Columns:** 20 · **Size:** 19.9 KB
- **Purpose:** HKU CoWIN station metadata
- **Source:** hk_cowin
- **station_id:** 164 distinct

| Column | Type | Non-null | Range / values | Description |
|---|---|---|---|---|
| `station_id` | str | 474/474 (100%) | 164 distinct; e.g. "1005" | AWS/CoWIN station identifier |
| `station_name` | str | 473/474 (100%) | 155 distinct; e.g. "Hon Wah College" | station name |
| `latitude` | float64 | 473/474 (100%) | range 22.21 .. 22.55 | requested station latitude |
| `longitude` | float64 | 473/474 (100%) | range 113.9 .. 114.3 | requested station longitude |
| `elevation` | float64 | 86/474 (18%) | range 3.3 .. 151.8 | station elevation (m) |
| `Jan` | str | 90/474 (19%) | values: Y | field |
| `Feb` | str | 88/474 (19%) | values: Y | field |
| `Mar` | str | 90/474 (19%) | values: Y | field |
| `Apr` | str | 84/474 (18%) | values: Y | field |
| `May` | str | 86/474 (18%) | values: Y | field |
| `Jun` | str | 83/474 (18%) | values: Y | field |
| `Jul` | str | 80/474 (17%) | values: Y | field |
| `Aug` | str | 84/474 (18%) | values: Y | field |
| `Sep` | str | 87/474 (18%) | values: Y | field |
| `Oct` | str | 88/474 (19%) | values: Y | field |
| `Nov` | str | 86/474 (18%) | values: Y | field |
| `Dec` | str | 88/474 (19%) | values: Y | field |
| `year` | float64 | 473/474 (100%) | range 2023 .. 2025 | year |
| `source` | str | 474/474 (100%) | values: hk_cowin | source dataset identifier |
| `metadata_missing` | object | 1/474 (0%) | values: True | TRUE when a rainfall station has no row in CoWIN available.csv |