Figure 1.Interactive map showing the locations of precipitation gauges deployed in Fort Collins, Loveland, and Lafayette for the WR 417 precipitation collection assignment in September 2025.
Precipitation Report
1 Background
As part of Class of 16, we deployed four manual rain gauge models, Tru-Chek, Taylor, Biuwing, Wedge, and Raskoo, across multiple observation sites in Fort Collins, Loveland, and Lafayette. My monitoring location was The Junction apartment complex. I installed the Biuwing rain gauge on top of a central sign structure situated within the complex. The installation site was positioned between two parallel rows of residential buildings oriented primarily east–west, with a perpendicular north–south corridor providing a relatively unobstructed vertical exposure. This configuration minimized interference from wind turbulence and roof overhangs, ensuring acceptable siting conditions for manual precipitation measurement.
Daily rainfall observations were collected from 29 August to 29 September 2025. Over the course of this monitoring period, several measurable precipitation events occurred, providing an adequate dataset for comparing gauge performance and site-specific rainfall variability.
Above is an interactive map showing the locations of precipitation gauges deployed in Fort Collins, Loveland, and Lafayette for the WR 417 precipitation collection assignment in September 2025. There were varied rainfall events throughout September, and at the end of August, we saw some of the biggest rain events.
2 Results
Initially, the data collection period was scheduled to begin on September 1. However, observations were started one to two weeks earlier because significant rain events were forecasted for late August. September in Colorado is typically a relatively dry month, with fewer and smaller precipitation events compared to other times of the year. In contrast, the 2025 season appeared somewhat anomalous, as several substantial rain events occurred both at the end of August and again toward the end of September.
Another important consideration in our dataset is the variability in gauge precision across sites. I was assigned the Biuwing rain gauge, which was straightforward to install but measured precipitation in coarse increments of 0.5 inches to 1 inch. While this level of resolution may be adequate in wetter climates with higher rainfall totals, it is less suitable for semi-arid regions like Colorado, where many locations receive only a few inches of precipitation per year. As a result, the limited precision of this gauge likely reduced the accuracy of small-event measurements and contributed some uncertainty to the recorded dataset.
Figure 2.Daily precipitation totals summed across all stations, shown separately for morning(AM) and evening (PM) observations. Hover to view exact values for each day.
3 Precipitation Event Comparisons
The boxplots illustrate how precipitation amounts varied across defined rainfall events when separated into AM and PM observations. AM readings show a higher median precipitation value than PM readings, indicating that morning measurements tended to capture slightly higher rainfall totals. The AM boxplot also displays a wider interquartile range, suggesting greater variability in event intensity across sites during morning observations. Several AM events include higher precipitation amounts reaching above 1.5 inches, demonstrating the presence of a few relatively strong morning rainfall events.
In contrast, the PM readings exhibit a narrower interquartile range and a slightly lower median, reflecting more consistent but generally smaller precipitation totals in the evening measurements. The PM data include an isolated high outlier exceeding 1.3 inches, showing that substantial rainfall did occur during some PM periods, but less frequently than in the morning.
Overall, the comparison indicates that AM precipitation events tended to be more variable and slightly more intense, whereas PM events were more consistent with fewer extreme values. These patterns may reflect differences in storm timing, localized rainfall patterns, or recording schedules across sites.
There was substantial variability in precipitation totals across the different student monitoring stations. These stations were distributed across a broad geographic area, which naturally introduced differences in local weather patterns and storm intensities. Precipitation was also recorded at two distinct times of day 7:00 AM and 7:00 PM which may have influenced the measurements due to diurnal storm timing or differences in when rainfall events occurred. Additionally, the completeness of the dataset varied by station; some sites reported nearly every observation, while others had occasional gaps, contributing further variability in the totals.
When comparing the student-collected data to the official Fort Collins precipitation gauge, most stations recorded seasonal totals of approximately 2 inches or more. Notably, the stations located in the Loveland area reported the highest precipitation amounts, suggesting that this region experienced more intense or more frequent rainfall during the study period than the Fort Collins and Lafayette sites.
Regarding temporal trends, the overall precipitation totals and the September-only totals do not differ dramatically across stations. While a few sites show slightly lower rainfall during September relative to the full August–September dataset, these differences are generally small. However, the time-series graph reveals that some of the most pronounced rainfall events—both in terms of intensity and spatial extent—occurred during September. This indicates that although September is climatologically drier in northern Colorado, the study period included several unusually strong late-season storms that contributed significantly to the observed precipitation patterns.
| Total Precipitation by Site | |
| Values in inches | |
| Site Name | Total P (in) |
|---|---|
| Base Camp | 2.83 |
| Z Crib | 2.19 |
| Rock House | 1.02 |
| Hydro Abode | 0.00 |
| MTV Cribs | 3.40 |
| Centaur Village | 1.45 |
| Casa Crestmore | 2.37 |
| Outpost | 1.52 |
| Fort Collins | 1.24 |
| Wyan-not | 2.68 |
| Hizzhouse | 2.57 |
| MRV | 2.64 |
| Junction | 2.00 |
| Wettest Wedge | 2.72 |
| Convolvulus Garden | 0.61 |
| Corner Council | 2.36 |
| Sunflower Lane | 2.80 |