Feature Specification: Monthly Weather Trends¶

Feature Branch: 1-monthly-weather-trends Created: 2025-11-27 Status: Draft Input: User description: "the application provides services to get average temperature and humidity per month over the year from the weather data in resources folder of the application. it also provides a service which will for a given month show the trend of temperature and humidity and most common weather condition in that month. the application on the webpage shows two charts side by side for average temperature and humidity over the year. it them provides user option to select a month to see the weather trends for that month"

Clarifications¶

Session 2025-11-27¶

Q: How should the application behave if multiple years of data are present in the resources folder? → A: Always use latest full year.
Q: How should partial months be handled when computing monthly averages? → A: Always compute if at least one observation.
Q: What time granularity should monthly trends use? → A: Daily values over the month.

User Scenarios & Testing (mandatory)¶

User Story 1 - View yearly averages (Priority: P1)¶

As a user, I want to see charts of average temperature and humidity per month over a full year so that I can quickly understand overall seasonal patterns.

Why this priority: This is the primary overview that anchors the rest of the experience and must exist before month-level exploration is useful.

Independent Test: A user can load the application, see two populated charts (temperature and humidity) covering all months in the available year, with no additional configuration.

Acceptance Scenarios:

Given valid weather data is present in the resources folder for a full year, When the user opens the application, Then they see a chart of average temperature per month over that year.
Given valid weather data is present in the resources folder for a full year, When the user opens the application, Then they see a chart of average humidity per month over that year, aligned by month with the temperature chart.
Given some months have missing records, When the user opens the application, Then those months are either clearly indicated as missing or omitted with a clear legend/explanation.

User Story 2 - Explore trends for a selected month (Priority: P2)¶

As a user, I want to select a specific month from the yearly overview and see detailed temperature and humidity trends, along with the most common weather condition for that month, so that I can better understand intra-month variability.

Why this priority: This story builds on the yearly overview and provides the core exploratory capability expected from the app.

Independent Test: A user can pick any month that has data and see a detailed view with time-based temperature and humidity values and a clear indication of the most common weather condition in that month.

Acceptance Scenarios:

Given the yearly overview is visible, When the user selects a month that has data, Then the application shows a trend view for that month with temperature values over time.
Given the yearly overview is visible, When the user selects a month that has data, Then the application shows a trend view for that month with humidity values over time.
Given the user has selected a month that has data, When the detailed trend view is displayed, Then the most common weather condition in that month (e.g., clear, cloudy, rainy) is clearly indicated.
Given the user selects a month without any data, When the application tries to show a trend view, Then the user sees a clear message stating that no data is available for that month.

User Story 3 - Understand data assumptions and limitations (Priority: P3)¶

As a user, I want to understand what data the charts are based on, including any gaps or limitations, so that I can interpret the results correctly.

Why this priority: Transparency about data coverage and assumptions builds trust in the analysis.

Independent Test: A user can, from the main page, find a concise explanation of data sources, coverage (which months/years), and how averages and trends are calculated.

Acceptance Scenarios:

Given the user is viewing the yearly overview, When they look for data information, Then they can see a description of where the weather data comes from (resources folder) and the coverage period (e.g., which year).
Given the user is viewing a specific month trend, When they check the data assumptions, Then they see how averages and "most common weather condition" are computed.

Edge Cases¶

What happens when there is no data at all in the resources folder?
What happens when there is data for multiple years (e.g., more than one year represented in the resources folder)? (By default, the system uses the latest full year.)
What happens when there is partial data for some months (e.g., only a few days recorded)? (The system still computes a monthly average if at least one observation exists.)
What happens when the data file contains invalid or out-of-range values (e.g., negative humidity, extremely high temperatures)?

Requirements (mandatory)¶

Functional Requirements¶

FR-001: The system MUST load weather data files from a designated resources folder within the application.
FR-002: The system MUST detect all years represented in the loaded data and automatically select the latest full year as the basis for yearly summaries.
FR-003: The system MUST compute, for each month in the automatically selected year, the average temperature using the loaded data.
FR-004: The system MUST expose a way for the UI layer to retrieve the per-month average temperature and humidity for the year as structured data.
FR-005: The system MUST provide a way for the UI layer to request, for a given month, a time-ordered series of temperature values for that month.
FR-006: The system MUST provide a way for the UI layer to request, for a given month, a time-ordered series of humidity values for that month.
FR-007: The system MUST compute, for a given month, the most common weather condition over that month and make it available to the UI layer.
FR-008: The system MUST present, on the main page, two charts side by side: one for average temperature per month over the year and one for average humidity per month over the year.
FR-009: The system MUST allow the user to select a month from the yearly charts or from a clearly visible control to trigger display of that months detailed trends.
FR-010: The system MUST display, for a selected month, a visual representation of temperature and humidity trends over time and the most common weather condition.
FR-011: The system MUST handle missing or invalid data gracefully, clearly indicating gaps or errors rather than failing silently.
FR-012: The system MUST make all calculations deterministic and reproducible when given the same input data.

Key Entities (include if feature involves data)¶

WeatherObservation: Represents a single recorded observation with attributes such as timestamp/date, temperature, humidity, and weather condition.
MonthlySummary: Represents aggregated data per month, including month identifier (e.g., 1–12), average temperature, and average humidity.
MonthlyTrend: Represents detailed data for a selected month, including a series of daily aggregated values (e.g., average temperature and humidity per day over the month) and the most common weather condition.

Success Criteria (mandatory)¶

Measurable Outcomes¶

SC-001: A first-time user can load the application and correctly describe the overall yearly patterns in temperature and humidity within 2 minutes of interaction.
SC-002: A user can select any month with available data and obtain a clear trend view (temperature and humidity over time plus most common condition) within 3 interactions (e.g., open app, select month).
SC-003: For a given stable data set in the resources folder, repeated runs produce identical monthly averages, trends, and most common conditions.
SC-004: Error states for missing or invalid data are surfaced in a way that at least 90% of test users can explain what went wrong without seeing a stack trace or technical error.