Sep 29, 2025

Weather CLI Application

Project Overview

Weather CLI is a command-line interface (CLI) application to view real-time weather information and 3-day weather forecasts. This application uses the OpenWeatherMap API and provides results with attractive display using colors and emojis.

Tech Stack

Technology	Purpose
Node.js	Runtime environment
axios	HTTP client for API requests
inquirer	Interactive CLI prompts
chalk	Colorful terminal output
dotenv	Environment variable management

Project Structure

weather-cli/
├── index.js              # Main application file
├── .env                  # Environment variables (gitignore)
├── .env.example          # Example environment file
├── package.json          # Dependencies & scripts
└── README.md             # Project documentation

Installation & Setup

Prerequisites

Node.js v12 or higher
npm or yarn
OpenWeatherMap API Key (free)

Step-by-Step Installation

1. Clone or Download Project

git clone https://github.com/BagasHtml/Weather-Cli.git
cd weather-cli

2. Initialize Node Project (if needed)

npm init -y

3. Install Dependencies

npm install axios inquirer@8.2.5 chalk dotenv

Note: We use inquirer@8.2.5 specifically to avoid compatibility issues with newer versions.

4. Setup API Key

a. Create a free account at OpenWeatherMap

b. Generate API key from your dashboard

c. Create .env file in the root folder:

touch .env

d. Add your API key to .env:

OPENWEATHER_API_KEY=your_api_key_here

Replace your_api_key_here with your actual API key from OpenWeatherMap.

5. Run the Application

node index.js

Common Errors & Solutions

❌ Error: “Cannot find module ‘axios/inquirer/chalk’”

Cause:

Dependencies not installed
npm install failed

Solution:

# Install all dependencies again
npm install axios inquirer@8.2.5 chalk dotenv

# Or install one by one
npm install axios
npm install inquirer@8.2.5
npm install chalk
npm install dotenv

❌ Error: “API key not set”

Cause:

.env file doesn’t exist
OPENWEATHER_API_KEY not defined in .env
Variable name is wrong

Solution:

# Create .env file with your API key
echo "OPENWEATHER_API_KEY=your_api_key_here" > .env

# Or edit manually
nano .env  # Linux/Mac
notepad .env  # Windows

❌ Error: “chalk.red is not a function”

Cause:

Using wrong chalk syntax
Incompatible chalk version

Solution:

Use the provided fixed code from this documentation
Ensure chalk syntax is: chalk.red("text") not chalk.red”text”`

❌ Error: “inquirer.prompt is not a function”

Cause:

Inquirer version is too new (9.0+)
Compatibility issue with CommonJS

Solution:

# Install specific version that works with CommonJS
npm install inquirer@8.2.5

❌ Error: “City not found”

Cause:

City name spelling is wrong
City doesn’t exist in OpenWeatherMap database
City name format is incorrect

Solution:

Correct spelling examples:
✓ Jakarta
✓ New York
✓ Tokyo
✓ London

Avoid:
✗ jakarta (use capital letter)
✗ nyc (use full name)

❌ Error: “API key is wrong”

Cause:

API key is invalid
API key has expired
API key doesn’t have proper permissions

Solution:

Regenerate API key from OpenWeatherMap dashboard
Make sure API key is copied correctly without spaces
Check that you’re using Free Tier

❌ Error: “Too many requests” (429 Error)

Cause:

Too many requests in a short time
OpenWeatherMap rate limit exceeded
Free tier has a limit of 60 requests/minute

Solution:

Wait a few seconds before making another request
Upgrade to paid plan if you need more requests
Add request throttling in your code

Features

1. Search Weather by City

User-friendly CLI prompt
Auto-validation
Support for cities worldwide

2. Current Weather Display

🌡️ Current temperature (Celsius)
☁️ Weather condition
🤔 Feels like temperature
💧 Humidity level
💨 Wind speed

3. 3-Day Forecast

Weather forecast for next 3 days
Maximum and minimum temperature per day
Expected weather condition
Local date format (Indonesia)

4. Colorful Terminal Output

Different colors for each information type
Emojis for better visualization
User-friendly messages

Usage Guide

Running the Application

node index.js

Application Flow

1. Application displays welcome message
   🌤️ Hello! What city's weather do you want to check?

2. Enter city name
   ? Enter city name: Jakarta

3. Application fetches data
   🔍 Searching for data...

4. Display current weather information
   🌍 Weather in Jakarta, ID
   🌡️ Temperature: 28°C
   ☁️ Condition: Partly cloudy
   ... (other info)

5. Display 3-day forecast
   📅 Weather forecast for next 3 days:
   Today: 30°/24°C - Partly cloudy
   Tomorrow: 29°/23°C - Rainy
   ... (other info)

6. Application ends with thank you message
   ✨ Thanks for using my app!

Example Cities to Search

Domestic Cities:
- Jakarta
- Bandung
- Surabaya
- Yogyakarta

International Cities:
- New York
- London
- Tokyo
- Singapore
- Paris
- Sydney

Code Explanation

Main Functions

cariKota(namaKota) - Search City

Searches for location coordinates using Geo API
Parameter: city name (string)
Returns: object with lat, lon, name, country
Error handling for city not found

ambilCuaca(lat, lon) - Get Current Weather

Fetches current weather data
Parameters: latitude and longitude
Returns: object with all weather data
Uses units=metric for Celsius

ambilPerkiraan(lat, lon) - Get Forecast

Fetches weather forecast data
Parameters: latitude and longitude
Returns: object with forecast data
Data for 5 days (120 hours)

tampilkanCuaca(cuaca, lokasi) - Display Current Weather

Format and display current weather
Uses chalk for colors
Uses emojis for visual appeal

tampilkanPerkiraan(perkiraan) - Display Forecast

Format and display 3-day forecast
Group data by day
Calculate min/max temperature per day

main() - Main Function

Orchestrate all processes
Prompt user for input
Handle errors gracefully
Use try-catch for error handling

Dependencies Explanation

axios

HTTP client for making API requests

const axios = require("axios");

// Usage:
const response = await axios.get(url);
const data = response.data;

inquirer

Interactive command-line prompts

const inquirer = require("inquirer");

// Usage:
const { kota } = await inquirer.prompt([
    {
        type: "input",
        name: "kota",
        message: "Enter city name:"
    }
]);

chalk

Colorful terminal output

const chalk = require("chalk");

// Usage:
console.log(chalk.red("Error message"));
console.log(chalk.blue("Info message"));
console.log(chalk.yellow("Warning message"));
console.log(chalk.green("Success message"));

dotenv

Load environment variables from .env file

require('dotenv').config();

// Usage:
const API_KEY = process.env.OPENWEATHER_API_KEY;

Environment Variables

`.env` File Format

OPENWEATHER_API_KEY=your_api_key_here

`.env.example` (for sharing)

OPENWEATHER_API_KEY=

Best Practices

✓ Never push .env to git (add to .gitignore)
✓ Use .env.example as a template
✓ Keep API key secret
✓ Use strong password for OpenWeatherMap account
✓ Regenerate key if exposed

API Integration

OpenWeatherMap APIs Used

1. Geo API (Location)

GET /geo/1.0/direct?q={city}&limit=1&appid={API_KEY}

Converts city name to coordinates
Accuracy: ±1km

2. Current Weather API

GET /data/2.5/weather?lat={lat}&lon={lon}&units=metric&appid={API_KEY}

Real-time weather data
Updates every 10 minutes

3. Forecast API

GET /data/2.5/forecast?lat={lat}&lon={lon}&units=metric&appid={API_KEY}

5-day weather forecast
Resolution: 3 hours

Terminal Output Examples

Success Output

🌤️ Hello! What city's weather do you want to check?

? Enter city name: Jakarta
🔍 Searching for data...

🌍 Weather in Jakarta, ID

🌡️ Temperature: 28°C
☁️ Condition: scattered clouds
🤔 Feels like: 31°C
💧 Humidity: 65%
💨 Wind: 3.5 m/s

📅 Weather forecast for next 3 days:

Today: 30°/24°C - Partly cloudy
Tomorrow: 29°/23°C - Rainy
Monday: 28°/22°C - Clear sky

✨ Thanks for using my app!

Error Output

❌ Hey! API key is not set!
Set up .env file with: OPENWEATHER_API_KEY=your_api_key

💥 Error: City "xyz" not found bro

Performance Optimization

Current Implementation

✓ Parallel requests using Promise.all()
✓ Efficient data filtering
✓ Minimal API calls

Potential Improvements

Security Considerations

✅ Best Practices

Keep API key in environment variables
Never commit .env file to git
Use HTTPS for API calls
Validate user input before API request

🔒 Environment Variable Security

# Good practice
export OPENWEATHER_API_KEY="your_key"

# Bad practice
OPENWEATHER_API_KEY="your_key"  # In source code

Troubleshooting Checklist

API key generated from OpenWeatherMap
.env file created correctly
All dependencies installed (npm install)
.env file is in root folder (not in subfolder)
City name spelled correctly (capitalize first letter)
Internet connection is active
API key is not expired
Rate limit not exceeded

Future Features

Package.json Template

{
  "name": "weather-cli",
  "version": "1.0.0",
  "description": "CLI application to check real-time weather",
  "main": "index.js",
  "type": "commonjs",
  "scripts": {
    "start": "node index.js"
  },
  "dependencies": {
    "axios": "^1.6.0",
    "inquirer": "^8.2.5",
    "chalk": "^4.1.2",
    "dotenv": "^16.0.0"
  }
}

Getting Your OpenWeatherMap API Key

Free Account Benefits

✓ Up to 60 requests per minute
✓ Current weather data
✓ 5-day forecast
✓ No credit card required
✓ No time limit

How to Get API Key

Visit OpenWeatherMap API
Click “Sign Up”
Fill in email and password
Verify your email
Login to your account
Go to “API Keys” section
Copy your “Default API Key”
Add to your .env file

License & Credits

API: OpenWeatherMap
CLI Framework: Inquirer.js
Styling: Chalk
HTTP Client: Axios
Environment: dotenv

Support & Feedback

If you encounter any issues or have questions:

Check this documentation first
Review the error message carefully
Verify your API key and internet connection
Reinstall dependencies if needed: npm install
Check the Troubleshooting Checklist

Version History

v1.0.0 (Current)

Initial release
Current weather display
3-day forecast
City search functionality
Colorful CLI output
Error handling

Glossary

Term	Definition
API Key	Unique identifier for API access
CLI	Command-Line Interface
Forecast	Predicted weather for future days
Geo API	Geolocation API for coordinates
Latitude	Horizontal map coordinate (North-South)
Longitude	Vertical map coordinate (East-West)
Rate Limit	Maximum requests allowed per time period
Environment Variables	Configuration values stored outside code

Weather CLI Application

Project Overview

Tech Stack

Project Structure

Installation & Setup

Prerequisites

Step-by-Step Installation

Common Errors & Solutions

❌ Error: “Cannot find module ‘axios/inquirer/chalk’”

❌ Error: “API key not set”

❌ Error: “chalk.red is not a function”

❌ Error: “inquirer.prompt is not a function”

❌ Error: “City not found”

❌ Error: “API key is wrong”

❌ Error: “Too many requests” (429 Error)

Features

1. Search Weather by City

2. Current Weather Display

3. 3-Day Forecast

4. Colorful Terminal Output

Usage Guide

Running the Application

Application Flow

Example Cities to Search

Code Explanation

Main Functions

Dependencies Explanation

axios

inquirer

chalk

dotenv

Environment Variables

.env File Format

.env.example (for sharing)

Best Practices

API Integration

OpenWeatherMap APIs Used

Terminal Output Examples

Success Output

Error Output

Performance Optimization

Current Implementation

Potential Improvements

Security Considerations

✅ Best Practices

🔒 Environment Variable Security

Troubleshooting Checklist

Future Features

Package.json Template

Getting Your OpenWeatherMap API Key

Free Account Benefits

How to Get API Key

License & Credits

Support & Feedback

Version History

v1.0.0 (Current)

Glossary

`.env` File Format

`.env.example` (for sharing)