TemperatureReading

Info

TemperatureReading is an interface representing a single temperature sensor reading from the host machine. Each reading corresponds to one physical sensor (CPU die, GPU hotspot, motherboard chipset, storage device, etc.) and is returned as part of a TemperatureSnapshot from the getTemperature() function.

Interface Introduction

You encounter TemperatureReading objects inside the readings array of a TemperatureSnapshot. Every sensor detected by the underlying LibreHardwareMonitor library produces one TemperatureReading entry. Use this interface to inspect individual sensor temperatures, filter by hardware category, or build temperature monitoring dashboards.

Properties

Property	Type	Description
id	string	Unique identifier for this sensor, stable across calls within the same session
label	string	Human-readable sensor name (e.g. "CPU Package", "GPU Core")
category	TemperatureCategory	Hardware category this sensor belongs to
temperatureCelsius	number	Current temperature in degrees Celsius
source	"libre-hardware-monitor"	Fixed data source identifier, always "libre-hardware-monitor"

Note

The id string is derived from the sensor's internal path in LibreHardwareMonitor. It remains consistent across consecutive calls but may change if the hardware topology changes (e.g. a USB device is plugged in).

Tips

Use the category property to group readings by hardware type rather than parsing the label string. The TemperatureCategory enum provides well-defined values ("cpu", "gpu", "motherboard", "storage", "unknown") that are more reliable than label-based heuristics.

Usage

TemperatureReading objects are read-only snapshots. You do not create them yourself; instead, call getTemperature() and iterate over the readings array of the returned TemperatureSnapshot.

A typical workflow:

1. Call getTemperature() to obtain the current TemperatureSnapshot.
2. Check snapshot.isAvailable to confirm LibreHardwareMonitor is running.
3. Access snapshot.readings to get the array of TemperatureReading objects.
4. Filter or display readings by category, label, or temperatureCelsius.

Tips

Temperature values are floating-point numbers in Celsius. To convert to Fahrenheit, use temp * 9 / 5 + 32. Avoid rounding before comparison to preserve precision.

Warning

When isAvailable is false on the parent TemperatureSnapshot, the readings array will be empty. Always check isAvailable before iterating.

Example

TypeScript

import { getTemperature, TemperatureReading } from '@eisland/windows-performance-monitor';

// Query the current temperature snapshot
const snapshot = getTemperature();

// Check if temperature data is available (requires LibreHardwareMonitor)
if (!snapshot.isAvailable) {
  console.log('Temperature data unavailable — is the helper EXE running?');
} else {
  // Iterate over all sensor readings
  snapshot.readings.forEach((r: TemperatureReading) => {
    // Pick a display icon based on the sensor category
    const icon = r.category === 'cpu' ? '[CPU]'
               : r.category === 'gpu' ? '[GPU]'
               : r.category === 'storage' ? '[STO]'
               : '[HW]';
    // Print the sensor label and current temperature
    console.log(`${icon} ${r.label}: ${r.temperatureCelsius}°C`);
  });

  // Filter readings to CPU sensors only
  const cpuReadings: TemperatureReading[] = snapshot.readings.filter(
    (r: TemperatureReading) => r.category === 'cpu'
  );
  console.log(`CPU sensors: ${cpuReadings.length}`);
}

JavaScript

const { getTemperature } = require('@eisland/windows-performance-monitor');

// Query the current temperature snapshot
const snapshot = getTemperature();

// Check if temperature data is available (requires LibreHardwareMonitor)
if (!snapshot.isAvailable) {
  console.log('Temperature data unavailable — is the helper EXE running?');
} else {
  // Iterate over all sensor readings
  snapshot.readings.forEach((r) => {
    // Pick a display icon based on the sensor category
    const icon = r.category === 'cpu' ? '[CPU]'
               : r.category === 'gpu' ? '[GPU]'
               : r.category === 'storage' ? '[STO]'
               : '[HW]';
    // Print the sensor label and current temperature
    console.log(`${icon} ${r.label}: ${r.temperatureCelsius}°C`);
  });

  // Filter readings to CPU sensors only
  const cpuReadings = snapshot.readings.filter(
    (r) => r.category === 'cpu'
  );
  console.log(`CPU sensors: ${cpuReadings.length}`);
}

Notes

Note

The source field is currently always "libre-hardware-monitor". Future versions may introduce additional data sources. Treat the value as a string rather than hard-coding equality checks if you want forward compatibility.

Note

Temperature readings are collected at the moment getTemperature() is called. There is no built-in polling or event-based update mechanism. To track temperature changes over time, call getTemperature() on your own interval.

Tips

If you only need the highest temperature across all sensors (for example, to display a single "system hot" indicator), use the maxTemperatureCelsius field on the parent TemperatureSnapshot instead of computing it yourself from the readings array.

Danger Avoidance

Caution

Do not assume temperatureCelsius is always a reasonable value. LibreHardwareMonitor may report 0 or negative values for sensors that are not actively reading. Always validate against expected ranges before using the value in threshold-based alerts or UI displays.

Caution

Calling getTemperature() in a tight loop (e.g. inside requestAnimationFrame or a zero-delay setInterval) will trigger repeated hardware polling via the LibreHardwareMonitor helper process. This wastes CPU cycles and can cause the helper EXE to become unresponsive. Poll at intervals of 1 second or longer.