About the Project -The Kigali Air Story

Project Overview

This dashboard analyzes air quality data from Kigali, Rwanda, focusing on PM2.5 measurements from reference monitors at the US embassy. For context, Kigali experienced low visibility and haze/smog in early January 2025, prompting interest in exploring the potential influence of particulate matter (PM) on these conditions. The data is sourced from Airnow.gov, providing valuable insights into the city's air quality patterns and trends. Unfortunately, the AirNow site showing the emabassies and consulates, where I downloaded this data, shows '404 not found', with no clear timeline for when it will be back online. Fortunately, the data needed for 2022–2025 for Kigali had been downloaded beforehand.

This analysis aims to identify notable trends in air quality data from Kigali, Rwanda, with a particular focus on the period between November 2024 and January 2025. During this timeframe, a slight increase in PM2.5 levels is observed; however, further investigation is needed to determine its statistical significance and potential causes. Notably, the data indicates that Kigali’s Air Quality Index (AQI) ranges from moderate to unhealthy for most of the year, with only a few days classified as 'good,' offering a detailed perspective on the city’s air quality dynamics.

Methodology

Data is collected through reference-grade monitors maintained by the US Embassy in Kigali. The measurements undergo quality control processes before being made available through Airnow.gov's system.

Visual Comparison

Image Comparison

Slightly Clear Day
Low visibility Day
Slightly Clear Day
Low visibility Day

The images in the visual comparison section were captured on two different days: February 26th and March 7th. In one image, the Amahoro Stadium and background hills are clearly visible, while in the other, visibility is slightly reduced. The Amahoro Stadium, annotated below, served as a landmark and reference point to align the images as closely as possible. Both photos were taken from the CMU-Africa campus.

Kigali City on a Clear Day

Data Analysis - 2024 Kigali Perspective

Data Quality and Coverage

  • Total valid readings: 2,647 (after filtering out negative values)
  • Consistent hourly measurements with approximately 110 readings per hour
  • Standard deviation of 17.04 µg/m³ indicates moderate variability in measurements

Temporal Patterns

  • Clear day-night variation:
    • Daytime average (6AM-6PM): 31.08 µg/m³
    • Nighttime average (6PM-6AM): 37.67 µg/m³
    • 21.2% higher concentrations during nighttime
  • Hourly patterns show peak concentrations in early morning hours (around 3-4 AM)

Distribution Characteristics

  • Mean PM2.5: 34.38 µg/m³
  • Maximum recorded value: 152.30 µg/m³
  • AQI Category breakdown:
    • Moderate: 57.5% of readings
    • Unhealthy for Sensitive Groups: 31.2%
    • Unhealthy: 10.3%
    • Good: 0.9%

Air Quality Perspective

Overall Air Quality Status

  • The average PM2.5 concentration of 34.38 µg/m³ exceeds WHO guidelines (annual guideline of 5 µg/m³)
  • Only 0.9% of readings fall in the "Good" category, indicating persistent air quality challenges
  • Over 41% of readings (Unhealthy + Unhealthy for Sensitive Groups) indicate significant health risks

Health Implications

  • The high proportion of "Unhealthy for Sensitive Groups" (31.2%) suggests regular risks for:
    • People with respiratory conditions
    • Elderly individuals
    • Children and pregnant women
  • 10.3% of readings in "Unhealthy" category indicate periods where general population may experience health effects

This chart gives an explanation of what the Air Quality Index (AQI) readings mean. If not familiar with the AQI find more information here: Understanding the Air Quality Index

AQI Chart
Data sourced from Airnow.gov, provided by the U.S. Environmental Protection Agency and the U.S. State Department’s air quality monitoring program. Data provided on as-is basis and does not verify the accuracy.