Quantifying species\' niches across a clade reveals how environmental tolerances evolve, and offers insights into present and future distributions. Niche construction occurs when species select subsets of suitable conditions from those available, and influences niche evolution. We use herbarium specimens to explore climate niche evolution in 14 annual species of the Streptanthus/Caulanthus clade (Brassicaceae), which originated in deserts and subsequently diversified into cooler, moister areas. We quantify the \"lived climate\" of specimens from germination, estimated from historical climate records at collection sites, to collection date. We compare these specimen-based, phenologically-specific climate niches to typical annual climate niches and to standardized seasonal niches from the same localities. We also explore the role of spatial microrefugia in shaping lived climate by analyzing field soil samples collected for each species, and by comparing soil texture at collection localities to random locations nearby using soil databases. Specimen-specific climate achieved through niche construction revealed much less clade-wide temperature niche variation than annual and seasonal niches. Species track hotter and drier climates in cooler regions by growing later into the summer, and by inhabiting spatial refugia of drought-prone soils. All climate metrics evolved in a manner consistent with or more constrained than Brownian motion except specimen-specific temperature niches, which showed limited clade-wide variation and no phylogenetic signal. Limited variation in specimen-specific climate niches across the clade underscores how niche construction moderates experienced climate and may impact species\' responses to climate change.