Overview

Project Summary

Public datasets are useful, but they rarely arrive in the exact shape needed for analysis. In this project, I worked through a NOAA weather dataset with multiple station files, inconsistent field availability, long historical date ranges, and many columns that were not needed for the final report.

The finished workbook focuses on a small set of selected stations and precipitation reporting. Behind that simple dashboard is a larger preparation workflow: identifying which files had usable columns, checking value ranges, filtering the dataset down to reporting fields, standardizing dates, and building pivot-based views for monthly, yearly, and semi-annual comparisons.

I built this as an Excel-centered project on purpose. Many businesses still run important reporting from Excel, and a strong Excel workflow can be extremely valuable when it is structured, documented, and supported by clean transformation logic.

Walkthrough

Video Overview

This project walkthrough shows the workbook structure, the Power Query workflow, and how the dashboard connects back to the prepared NOAA weather data.

Business Problem

What This Workflow Needed To Solve

The real challenge was not making a line chart. The challenge was getting from a folder of raw files to a reliable reporting table while keeping enough visibility into the process to trust the output. That is the kind of work that often sits between analytics, operations, and reporting.

  • Which source files contain the fields needed for reporting?
  • Which columns are consistent enough to keep?
  • Are the date fields usable across a long historical range?
  • Can station metadata such as latitude and longitude support map-based context?
  • How can the raw dataset be reduced into a smaller reporting table without losing the important fields?
  • What seasonal and long-term precipitation patterns are visible by station?
  • Can the final workbook remain explainable to someone reviewing it later?

Data Profiling

Understanding The Raw Files Before Building The Report

Before building visuals, I profiled the files to understand their row counts, column counts, available fields, and basic value ranges. This step helped separate useful reporting fields from noise before the data reached the dashboard.

Excel file profiling sheet showing file names, row counts, column counts, and available columns
File-level profiling to compare row counts, column counts, and available fields across source files.
Excel column profile sheet showing column names, file counts, and source files where each column appears
Column profiling to identify which fields appeared consistently enough to support reporting.
Excel value range profile showing minimum and maximum values for weather-related columns
Value range checks to spot date ranges, measurement ranges, and fields that needed closer review.

Power Query Workflow

Turning Many Files Into A Reporting Table

Power Query handled the repeatable transformation work: loading the source files, keeping only the files and columns needed, parsing CSV content, promoting headers, standardizing dates, adding calendar fields, and applying final data types.

Power Query editor showing transformation steps for the Mini WeatherData query
The query steps show the workflow from source intake through date parsing, month and year extraction, and final type cleanup.

This is one of the most important parts of the project because it shows the reporting layer was not assembled manually. The workbook has a repeatable cleanup path, which is what makes the final dashboard more useful than a one-off spreadsheet.

Prepared Dataset

A Smaller, Cleaner Dataset Built For Analysis

After the source files were reduced and transformed, the reporting table included the key station, date, location, and precipitation fields needed for the workbook.

Prepared Excel table with station, date, latitude, longitude, elevation, station name, precipitation, year, month number, month, and date fields
Prepared station-level weather data with standardized date fields and reporting-friendly calendar columns.

Location Context

Adding Geographic Context To The Station Data

The station latitude and longitude fields were used to show where the selected weather stations are located. This gives the report more context than a table of station names alone.

Excel sheet showing station locations, latitude and longitude values, and a map of weather station points across the United States
Station location table and map view showing the geographic spread of the selected reporting stations.

Dashboard

Historical Weather Reporting Dashboard

The final dashboard brings together monthly patterns, long-term station trends, map context, and semi-annual comparison views into a single reporting page.

Historical weather reporting dashboard showing monthly precipitation, historical precipitation trends, station map, and semi-annual trend chart
Final Excel dashboard combining pivot charts, station filtering, a timeline, location context, and precipitation trends.

This view gives a reviewer several ways to view the data: seasonal behavior by month, long-term annual movement by station, station geography, and selected semi-annual comparisons.

Analysis Views

Pivot-Based Views Used To Build The Story

The supporting worksheet views show the analysis behind the dashboard. They are intermediate views which feed into the main report page and are used to validate it.

Excel pivot table and line chart showing average precipitation by year and station
The yearly station trend view compares precipitation behavior across the selected stations.
Excel pivot table and chart showing average precipitation by month and station
The monthly average view shows how precipitation patterns differ by station throughout the year.
Excel pivot table and chart comparing June and December precipitation over time
The semi-annual comparison view focused on how rainfall differs bi-annually across the historical date range.

Design Decisions

Why The Workbook Was Structured This Way

Profile Before Reporting

The file and column profiling sheets made the dataset easier to reason about before building visuals. This reduced guesswork and helped identify which fields were stable enough to use.

Keep The Final Dataset Narrow

The reporting table was intentionally reduced to the fields needed for analysis during preprocessing. Station identity, date fields, location fields, and precipitation values were identified as stable fields across the specified reports imported by the dataset.

Use Excel Strengths

Pivot tables, slicers, timelines, charts, and maps were used where they made sense instead of forcing every step into a heavier BI platform.

Show The Workflow

The workbook includes visible preparation and analysis layers so the final dashboard is easier to audit, explain, and improve later.

Key Takeaways

What This Project Demonstrates

  • Raw public datasets often need a profiling step before they are safe to use in a dashboard.
  • Power Query can turn a folder-based data source into a repeatable reporting workflow instead of a process requiring extensive manual pre-transformation.
  • Excel can still be a strong reporting tool when the workbook is structured around clean source data, pivot-based analysis, and clear dashboard sections.
  • Location metadata added useful context and helped make the station comparison easier to understand.
  • The project shows both technical cleanup work and business-facing reporting, which is the combination many real reporting projects require.

Tools Used

Technology Stack

Excel

Pivot tables, pivot charts, slicers, timelines, map visuals, workbook organization, and dashboard presentation.

Power Query

Folder ingestion, CSV parsing, column selection, date parsing, calendar fields, filtering, cleanup, and final data typing.

Data Profiling

File-level review, column availability checks, value range checks, and source structure analysis before dashboard development.

Outcome

Reporting Scope

The final workbook demonstrates a full Excel reporting workflow. This includes source file review, data profiling, Power Query transformation, prepared reporting tables, geographic context, pivot analysis, and dashboard design.

This kind of workflow is useful when a team needs more than a chart but does not necessarily need a full application. It creates a clear bridge between raw files and repeatable reporting, while keeping the logic visible enough for review and future improvement.

The project also shows the type of practical reporting work I focus on. Take messy data, make it understandable, and turn it into a dashboard or workbook that supports better analysis.