ksmesopy 0.1.1

Python API for the Kansas Mesonet

ksmesopy

Python package for downloading and processing data from the Kansas Mesonet, an environmental monitoring network operated by Kansas State University.

Installation

pip install ksmesopy

Dependencies: numpy, pandas, matplotlib. The desktop app additionally requires guile.

Quick start

import ksmesopy as ms

# Download daily temperature and precipitation for one station
df = ms.request_data(
    station="Manhattan",
    start="2024-01-01",
    end="2024-12-31",
    interval="day",
    variables=["TEMP2MAVG", "TEMP2MMIN", "TEMP2MMAX", "PRECIP"],
)

# Optional: rename columns to snake_case
df = ms.rename_columns(df)
# TIMESTAMP → timestamp, TEMP2MAVG → t2m, PRECIP → precip, …

Desktop app

python ksmesoapp.py

A GUI for selecting stations, date ranges, variables, and intervals, with a tabular view and time-series chart. Exports to CSV and PNG.

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API reference

Stations

Function	Returns	Description
get_stations()	DataFrame	Full station metadata table
get_stations(names_only=True)	list[str]	Sorted list of station names only
get_stations_active()	DataFrame	Availability table: STATION, OBS_INTERVAL (s), START, END

Data retrieval

Function	Returns	Description
request_data(station, start, end, interval, variables, *, verbose, sleep)	DataFrame	Download data for one station. interval is "day", "hour", or "5min". Daily timestamps are corrected from the Mesonet's next-day convention.
request_data_multi(stations, start, end, interval, variables, *, verbose, sleep)	dict[str, DataFrame]	Same as above for a list of stations; returns one DataFrame per station.
list_variables(interval=None)	list[dict]	Variable catalogue filtered by interval, or all variables if None. Each entry has keys api_name, snake_name, description, intervals.
rename_columns(df, preset="snake")	DataFrame	Rename API column names to snake_case (e.g. TEMP2MAVG → t2m). Pass a dict for a custom mapping.

Soil processing

Function	Returns	Description
calibrate_vwc(df, vwc_cols=None)	DataFrame	Replace firmware VWC values with the KSU site-specific calibration. Fetch SOILKA*CM and SOILEC*CM alongside VWC*CM in the same request_data call. Works on any subset of depths.
compute_soil_water_storage(df)	DataFrame	Trapezoidal soil water storage in the top 50 cm (mm). Requires all four VWC depths; adds a STORAGE_MM column. Call calibrate_vwc() first for calibrated storage.

Derived variables

Function	Returns	Description
growing_degree_days(tmin, tmax, base=10.0, ceiling=30.0)	ndarray	Daily GDD. Both tmin/tmax clipped to [base, ceiling] before averaging.
heat_index(temp, rh)	ndarray	NOAA/NWS apparent temperature (°C).
wind_chill(temp, wspd)	ndarray	NWS wind chill (°C); valid for temp ≤ 10 °C, wind ≥ 1.3 m s⁻¹.
temperature_humidity_index(temp, rh)	ndarray	THI for livestock heat stress. Thresholds (dairy): <68 none · 68–72 mild · 72–80 moderate · 80–90 severe · >90 dangerous.

Reference evapotranspiration

Function	Returns	Description
reference_et_penman_monteith(doy, lat, elev, tmin, tmax, srad, wspd, rhmin, rhmax, *, vpd, ea, wind_height)	(ETo, Ra)	FAO-56 Penman-Monteith. Supply vapour pressure via ea=, vpd=, or rhmin=+rhmax=. srad in W m⁻², converted internally.
reference_et_hargreaves(doy, lat, tmin, tmax, *, tmean)	(ETo, Ra)	Hargreaves–Samani. Temperature only — no humidity, radiation, or wind needed.

Both return (ETo [mm day⁻¹], Ra [MJ m⁻² day⁻¹]).

Atmospheric helpers

Function	Output
saturation_vapor_pressure(temp)	es (kPa)
actual_vapor_pressure(temp, rh)	ea (kPa)
vapor_pressure_deficit(temp, rh)	VPD (kPa, ≥ 0)
slope_saturation_vapor_pressure(temp)	Δ (kPa °C⁻¹)
atmospheric_pressure(elev)	P (kPa)
psychrometric_constant(elev)	γ (kPa °C⁻¹)
extraterrestrial_radiation(doy, lat)	Ra (MJ m⁻² day⁻¹)
net_radiation(srad_mj, tmin, tmax, ea, elev, doy, lat)	Rn (MJ m⁻² day⁻¹)
srad_to_mj(srad, period)	energy (MJ m⁻²)

All functions accept scalars or NumPy arrays.

Charts

Each function draws onto a Matplotlib Axes supplied by the caller, so panels compose freely inside any figure layout. All functions accept API column names (TEMP2MAVG) or snake_case names (t2m) interchangeably, and return the axes they drew on so they can be further customised.

import matplotlib.pyplot as plt
import ksmesopy as ms

fig, axes = plt.subplots(5, 1, sharex=True, figsize=(12, 14))

ms.plot_temperature(axes[0], df, ["TEMP2MAVG", "TEMP2MMIN", "TEMP2MMAX"])
ms.plot_precip(axes[1], df, "PRECIP")
ms.plot_humidity(axes[2], df, "RELHUM2MAVG")
ms.plot_solar_radiation(axes[3], df, ["SRAVG", "Ra"])  # Ra drawn dashed
ms.plot_vwc(axes[4], df)                               # auto-detects VWC columns

plt.tight_layout()
plt.savefig("meteogram.png", dpi=150)

plt.tight_layout() plt.savefig("meteogram.png", dpi=150)

All functions accept API column names (`TEMP2MAVG`) or snake_case names (`t2m`) interchangeably, and return the axes they drew on so they can be further customised.

| Function | Key behaviour |
|---|---|
| `plot_temperature(ax, df, variables, *, band, ylabel, legend)` | Shaded band when min/avg/max triplet detected (`band=True`); plain lines otherwise. Works for air and soil temperature. |
| `plot_precip(ax, df, variable, *, ylabel, color)` | Bar chart, bar width inferred from timestamp spacing. |
| `plot_humidity(ax, df, variables, *, ylabel, legend)` | Lines, y-axis fixed 0–100 %. |
| `plot_vpd(ax, df, variables, *, ylabel, legend)` | Filled area + line, y-axis starts at 0. |
| `plot_solar_radiation(ax, df, variables, *, ylabel, legend)` | Filled area for observed; dashed line for Ra columns (detected by name). |
| `plot_wind(ax, df, speed, direction, *, ylabel, legend)` | Speed as line; direction overlaid as scatter on a twin y-axis with N/E/S/W ticks. |
| `plot_vwc(ax, df, variables, *, ylabel, legend)` | Sequential colormap shallow→deep; auto-detects VWC columns if `variables=None`. |
| `plot_et(ax, df, variables, *, bar, ylabel, legend)` | Line by default; `bar=True` for daily totals. |

---

## Variable catalogue

Intervals: **D** = daily only · **H** = hourly and daily · **A** = 5-min, hourly, and daily

### Atmospheric

| API name | snake_case | Description | Unit | Intervals |
|---|---|---|---|---|
| `TEMP2MAVG` | `t2m` | Air temperature 2 m avg | °C | A |
| `TEMP2MMIN` | `t2m_min` | Air temperature 2 m min | °C | D |
| `TEMP2MMAX` | `t2m_max` | Air temperature 2 m max | °C | D |
| `TEMP10MAVG` | `t10m` | Air temperature 10 m avg | °C | A |
| `TEMP10MMIN` | `t10m_min` | Air temperature 10 m min | °C | D |
| `TEMP10MMAX` | `t10m_max` | Air temperature 10 m max | °C | D |
| `RELHUM2MAVG` | `rh` | Relative humidity 2 m avg | % | A |
| `RELHUM2MMIN` | `rh_min` | Relative humidity 2 m min | % | D |
| `RELHUM2MMAX` | `rh_max` | Relative humidity 2 m max | % | D |
| `VPDEFAVG` | `vpd` | Vapor pressure deficit avg | kPa | A |
| `PRESSUREAVG` | `pres` | Atmospheric pressure avg | kPa | A |
| `PRECIP` | `precip` | Precipitation gauge 1 | mm | A |
| `PRECIP2` | `precip2` | Precipitation gauge 2 | mm | A |
| `SRAVG` | `srad` | Solar radiation avg | W m⁻² | A |
| `WSPD2MAVG` | `wspd` | Wind speed 2 m avg | m s⁻¹ | A |
| `WSPD2MMAX` | `wspd_max` | Wind speed 2 m max | m s⁻¹ | H¹ |
| `WDIR2M` | `wdir` | Wind direction 2 m | ° | A |
| `WDIR2MSTD` | `wdir_std` | Wind direction 2 m std dev | ° | A |
| `WSPD10MAVG` | `wspd10m` | Wind speed 10 m avg | m s⁻¹ | A |
| `WSPD10MMAX` | `wspd10m_max` | Wind speed 10 m max | m s⁻¹ | H¹ |
| `WDIR10M` | `wdir10m` | Wind direction 10 m | ° | A |
| `WDIR10MSTD` | `wdir10m_std` | Wind direction 10 m std dev | ° | A |

¹ Available at 5-min and daily only (not hourly).

### Soil temperature — dedicated probes

| API name | snake_case | Description | Unit | Intervals |
|---|---|---|---|---|
| `SOILTMP5AVG` | `tsoil_5cm` | Soil temperature 5 cm avg | °C | A |
| `SOILTMP5MIN` | `tsoil_5cm_min` | Soil temperature 5 cm min | °C | D |
| `SOILTMP5MAX` | `tsoil_5cm_max` | Soil temperature 5 cm max | °C | D |
| `SOILTMP10AVG` | `tsoil_10cm` | Soil temperature 10 cm avg | °C | A |
| `SOILTMP10MIN` | `tsoil_10cm_min` | Soil temperature 10 cm min | °C | D |
| `SOILTMP10MAX` | `tsoil_10cm_max` | Soil temperature 10 cm max | °C | D |

### Soil — CS655 sensors

| API name | snake_case | Description | Unit | Intervals |
|---|---|---|---|---|
| `SOILTMP5AVG655` | `tsoil_5cm_655` | Soil temperature 5 cm | °C | A |
| `SOILTMP10AVG655` | `tsoil_10cm_655` | Soil temperature 10 cm | °C | A |
| `SOILTMP20AVG655` | `tsoil_20cm_655` | Soil temperature 20 cm | °C | A |
| `SOILTMP50AVG655` | `tsoil_50cm_655` | Soil temperature 50 cm | °C | A |
| `SOILKA5CM` | `ka_5cm` | Dielectric constant 5 cm | — | A |
| `SOILKA10CM` | `ka_10cm` | Dielectric constant 10 cm | — | A |
| `SOILKA20CM` | `ka_20cm` | Dielectric constant 20 cm | — | A |
| `SOILKA50CM` | `ka_50cm` | Dielectric constant 50 cm | — | A |
| `SOILEC5CM` | `ec_5cm` | Electrical conductivity 5 cm | dS m⁻¹ | A |
| `SOILEC10CM` | `ec_10cm` | Electrical conductivity 10 cm | dS m⁻¹ | A |
| `SOILEC20CM` | `ec_20cm` | Electrical conductivity 20 cm | dS m⁻¹ | A |
| `SOILEC50CM` | `ec_50cm` | Electrical conductivity 50 cm | dS m⁻¹ | A |
| `VWC5CM` | `vwc_5cm` | Volumetric water content 5 cm | m³ m⁻³ | A |
| `VWC10CM` | `vwc_10cm` | Volumetric water content 10 cm | m³ m⁻³ | A |
| `VWC20CM` | `vwc_20cm` | Volumetric water content 20 cm | m³ m⁻³ | A |
| `VWC50CM` | `vwc_50cm` | Volumetric water content 50 cm | m³ m⁻³ | A |

> **VWC note:** the Mesonet API returns VWC computed by the CS655 firmware equation. Requesting any `VWC*CM` column will print a warning reminding you that a site-specific calibration is available. To apply it, fetch the corresponding `SOILKA*CM` and `SOILEC*CM` columns in the same `request_data` call and then pass the DataFrame to `calibrate_vwc()`. Works for any subset of depths independently.

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## Notes

**Precipitation.** The Mesonet operates dual tipping-bucket rain gauges at most stations. `request_data()` returns both (`PRECIP`, `PRECIP2`); the desktop app merges them to the row-wise maximum automatically. For scripted use, merge manually:

```python
df["PRECIP"] = df[["PRECIP", "PRECIP2"]].max(axis=1)
df.drop(columns="PRECIP2", inplace=True)

Daily timestamps. The Mesonet API stores each day's aggregated values at 00:00 of the following calendar day. request_data() corrects for this automatically; the returned TIMESTAMP always reflects the observation date.

Missing values. The API encodes missing observations as "M". These are converted to NaN on read. Periods before a station or sensor was installed are pre-filled with NaN rather than omitted.

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License

MIT