dpearson2699/weatherkit

WeatherKit

Fetch current conditions, hourly and daily forecasts, weather alerts, and historical statistics using WeatherService. Display required Apple Weather attribution. Targets Swift 6.3 / iOS 26+.

Contents

• Setup
• Fetching Current Weather
• Forecasts
• Weather Alerts
• Selective Queries
• Attribution
• Availability
• Common Mistakes
• Review Checklist
• References

Setup

Project Configuration

1. Enable the WeatherKit capability in Xcode (adds the entitlement)
2. Enable WeatherKit for your App ID in the Apple Developer portal
3. Add NSLocationWhenInUseUsageDescription to Info.plist if using device location
4. WeatherKit requires an active Apple Developer Program membership

Import

import WeatherKit
import CoreLocation

Creating the Service

Use the shared singleton or create an instance. The service is Sendable and thread-safe.

let weatherService = WeatherService.shared
// or
let weatherService = WeatherService()

Fetching Current Weather

Fetch current conditions for a location. Returns a Weather object with all available datasets.

func fetchCurrentWeather(for location: CLLocation) async throws -> CurrentWeather {
    let weather = try await weatherService.weather(for: location)
    return weather.currentWeather
}

// Using the result
func displayCurrent(_ current: CurrentWeather) {
    let temp = current.temperature  // Measurement<UnitTemperature>
    let condition = current.condition  // WeatherCondition enum
    let symbol = current.symbolName  // SF Symbol name
    let humidity = current.humidity  // Double (0-1)
    let wind = current.wind  // Wind (speed, direction, gust)
    let uvIndex = current.uvIndex  // UVIndex

    print("\(condition): \(temp.formatted())")
}

Forecasts

Hourly Forecast

Returns 25 contiguous hours starting from the current hour by default.

func fetchHourlyForecast(for location: CLLocation) async throws -> Forecast<HourWeather> {
    let weather = try await weatherService.weather(for: location)
    return weather.hourlyForecast
}

// Iterate hours
for hour in hourlyForecast {
    print("\(hour.date): \(hour.temperature.formatted()), \(hour.condition)")
}

Daily Forecast

Returns 10 contiguous days starting from the current day by default.

func fetchDailyForecast(for location: CLLocation) async throws -> Forecast<DayWeather> {
    let weather = try await weatherService.weather(for: location)
    return weather.dailyForecast
}

// Iterate days
for day in dailyForecast {
    print("\(day.date): \(day.lowTemperature.formatted()) - \(day.highTemperature.formatted())")
    print("  Condition: \(day.condition), Precipitation: \(day.precipitationChance)")
}

Custom Date Range

Request forecasts for specific date ranges using WeatherQuery.

func fetchExtendedForecast(for location: CLLocation) async throws -> Forecast<DayWeather> {
    let startDate = Date.now
    let endDate = Calendar.current.date(byAdding: .day, value: 10, to: startDate)!

    let forecast = try await weatherService.weather(
        for: location,
        including: .daily(startDate: startDate, endDate: endDate)
    )
    return forecast
}

Weather Alerts

Fetch active weather alerts for a location. Alerts include severity, summary, and affected regions.

func fetchAlerts(for location: CLLocation) async throws -> [WeatherAlert]? {
    let weather = try await weatherService.weather(for: location)
    return weather.weatherAlerts
}

// Process alerts
if let alerts = weatherAlerts {
    for alert in alerts {
        print("Alert: \(alert.summary)")
        print("Severity: \(alert.severity)")
        print("Region: \(alert.region)")
        if let detailsURL = alert.detailsURL {
            // Link to full alert details
        }
    }
}

Selective Queries

Fetch only the datasets you need to minimize API usage and response size. Each WeatherQuery type maps to one dataset.

Single Dataset

let current = try await weatherService.weather(
    for: location,
    including: .current
)
// current is CurrentWeather

Multiple Datasets

let (current, hourly, daily) = try await weatherService.weather(
    for: location,
    including: .current, .hourly, .daily
)
// current: CurrentWeather, hourly: Forecast<HourWeather>, daily: Forecast<DayWeather>

Minute Forecast

Available in limited regions. Returns precipitation forecasts at minute granularity for the next hour.

let minuteForecast = try await weatherService.weather(
    for: location,
    including: .minute
)
// minuteForecast: Forecast<MinuteWeather>?  (nil if unavailable)

Available Query Types

| Query | Return Type | Description | |---|---|---| | .current | CurrentWeather | Current observed conditions | | .hourly | Forecast<HourWeather> | 25 hours from current hour | | .daily | Forecast<DayWeather> | 10 days from today | | .minute | Forecast<MinuteWeather>? | Next-hour precipitation (limited regions) | | .alerts | [WeatherAlert]? | Active weather alerts | | .availability | WeatherAvailability | Dataset availability for location |

Attribution

Apple requires apps using WeatherKit to display attribution. This is a legal requirement.

Fetching Attribution

func fetchAttribution() async throws -> WeatherAttribution {
    return try await weatherService.attribution
}

Displaying Attribution in SwiftUI

import SwiftUI
import WeatherKit

struct WeatherAttributionView: View {
    let attribution: WeatherAttribution
    @Environment(\.colorScheme) private var colorScheme

    var body: some View {
        VStack {
            // Display the Apple Weather mark
            AsyncImage(url: markURL) { image in
                image
                    .resizable()
                    .scaledToFit()
                    .frame(height: 20)
            } placeholder: {
                EmptyView()
            }

            // Link to the legal attribution page
            Link("Weather data sources", destination: attribution.legalPageURL)
                .font(.caption2)
                .foregroundStyle(.secondary)
        }
    }

    private var markURL: URL {
        colorScheme == .dark
            ? attribution.combinedMarkDarkURL
            : attribution.combinedMarkLightURL
    }
}

Attribution Properties

| Property | Use | |---|---| | combinedMarkLightURL | Apple Weather mark for light backgrounds | | combinedMarkDarkURL | Apple Weather mark for dark backgrounds | | squareMarkURL | Square Apple Weather logo | | legalPageURL | URL to the legal attribution web page | | legalAttributionText | Text alternative when a web view is not feasible | | serviceName | Weather data provider name |

Availability

Check which weather datasets are available for a given location. Not all datasets are available in all countries.

func checkAvailability(for location: CLLocation) async throws {
    let availability = try await weatherService.weather(
        for: location,
        including: .availability
    )

    // Check specific dataset availability
    if availability.alertAvailability == .available {
        // Safe to fetch alerts
    }

    if availability.minuteAvailability == .available {
        // Minute forecast available for this region
    }
}

Common Mistakes

DON'T: Ship without Apple Weather attribution

Omitting attribution violates the WeatherKit terms of service and risks App Review rejection.

// WRONG: Show weather data without attribution
VStack {
    Text("72F, Sunny")
}

// CORRECT: Always include attribution
VStack {
    Text("72F, Sunny")
    WeatherAttributionView(attribution: attribution)
}

DON'T: Fetch all datasets when you only need current conditions

Each dataset query counts against your API quota. Fetch only what you display.

// WRONG: Fetches everything
let weather = try await weatherService.weather(for: location)
let temp = weather.currentWeather.temperature

// CORRECT: Fetch only current conditions
let current = try await weatherService.weather(
    for: location,
    including: .current
)
let temp = current.temperature

DON'T: Ignore minute forecast unavailability

Minute forecasts return nil in unsupported regions. Force-unwrapping crashes.

// WRONG: Force-unwrap minute forecast
let minutes = try await weatherService.weather(for: location, including: .minute)
for m in minutes! { ... } // Crash in unsupported regions

// CORRECT: Handle nil
if let minutes = try await weatherService.weather(for: location, including: .minute) {
    for m in minutes { ... }
} else {
    // Minute forecast not available for this region
}

DON'T: Forget the WeatherKit entitlement

Without the capability enabled, WeatherService calls throw at runtime.

// WRONG: No WeatherKit capability configured
let weather = try await weatherService.weather(for: location) // Throws

// CORRECT: Enable WeatherKit in Xcode Signing & Capabilities
// and in the Apple Developer portal for your App ID

DON'T: Make repeated requests without caching

Weather data updates every few minutes, not every second. Cache responses to stay within API quotas and improve performance.

// WRONG: Fetch on every view appearance
.task {
    let weather = try? await fetchWeather()
}

// CORRECT: Cache with a staleness interval
actor WeatherCache {
    private var cached: CurrentWeather?
    private var lastFetch: Date?

    func current(for location: CLLocation) async throws -> CurrentWeather {
        if let cached, let lastFetch,
           Date.now.timeIntervalSince(lastFetch) < 600 {
            return cached
        }
        let fresh = try await WeatherService.shared.weather(
            for: location, including: .current
        )
        cached = fresh
        lastFetch = .now
        return fresh
    }
}

Review Checklist

• [ ] WeatherKit capability enabled in Xcode and Apple Developer portal
• [ ] Active Apple Developer Program membership (required for WeatherKit)
• [ ] Apple Weather attribution displayed wherever weather data appears
• [ ] Attribution mark uses correct color scheme variant (light/dark)
• [ ] Legal attribution page linked or legalAttributionText displayed
• [ ] Only needed WeatherQuery datasets fetched (not full weather(for:) when unnecessary)
• [ ] Minute forecast handled as optional (nil in unsupported regions)
• [ ] Weather alerts checked for nil before iteration
• [ ] Responses cached with a reasonable staleness interval (5-15 minutes)
• [ ] WeatherAvailability checked before fetching region-limited datasets
• [ ] Location permission requested before passing CLLocation to service
• [ ] Temperature and measurements formatted with Measurement.formatted() for locale

References

• Extended patterns (SwiftUI dashboard, charts integration, historical statistics): references/weatherkit-patterns.md
• WeatherKit framework
• WeatherService
• WeatherAttribution
• WeatherQuery
• CurrentWeather
• Forecast
• HourWeather
• DayWeather
• WeatherAlert
• WeatherAvailability
• Fetching weather forecasts with WeatherKit